Polymers made with metal oxide sols

ABSTRACT

In one embodiment, the present invention relates to a polymer prepared from a mixture containing a polymerization material and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor. In another embodiment, the present invention relates to a process for making a polymer involving contacting a polymerization material with a metal oxide sol comprising a liquid and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor to form a mixture and at least one of polymerizing and curing the mixture of the polymerization material and the polycondensation product.

This application is a continuation of Ser. No. 08/801,832, filed Feb.14, 1997, now U.S. Pat. No. 5,780,525.

FIELD OF THE INVENTION

The invention relates to polymers made with metal oxide sols. Morespecifically, the invention relates to polymers made with metal oxidesols, prepolymer mixtures containing a metal oxide sol and processes formaking a polymer with a metal oxide sol.

BACKGROUND OF THE INVENTION

It is known to incorporate filler type additives into polymers as ameans of enhancing the properties of the polymer or as a means ofimparting new properties to the polymer. For instance, it is known toadd silica filler to resins in an attempt to improve the physicalproperties of the resin.

As a specific example, curable electrical component coatings includeinorganic additives to achieve the desired surface electrical stressendurance. Such inorganic additive materials include alumina, silica andfumed metal oxide particulate additives and other non-transparentmaterials. Many inorganic additives are by nature resistive to hightemperature processing, both in production and in use, and they areresistive to oxidative degradation. Most inorganic additives, however,due to their compositional and physical makeup, require the use of highshear mixing when incorporated into a polymer to achieve a uniform,homogeneous composition. High shear mixing inherently creates voids inthe resulting polymer coating due to the entrapment of air in theprotective polymer coating mixture. The presence of voids in the curedpolymer coating allows corona generation which attacks the underlyingsubstrate and degrades the polymer coating itself under electricalstress when in use. Accordingly, it is desired to provide an additivewhich does not require high shear mixing and/or which does not lead tothe presence of voids in a polymer which it is incorporated.

In photocurable resin systems, using non-transparent material additiveswith photocure processing techniques results in non-uniform curing, asthe light energy curing agent may unevenly penetrate the curable resin,due to particle blockage and scattering, thus curing some resin segmentsand not curing others. Another problem caused by the same uneven,non-uniform penetration of the various additives is the premature cureof the resin. When using a photo initiated curing process, it isgenerally necessary to have particles of less than 0.2 microns.Particles in excess of 0.2 microns are capable of scattering light, thuspotentially resulting in uneven curing. Commercially availableparticulate fillers which require high speed mixing to maintainhomogeneity tend to agglomerate causing regions of higher particleconcentration and regions of lower concentration. This can lead toaccelerated oxidation in the particle-poor regions. Accordingly, it isdesired to provide an additive which does not agglomerate, which issmall in size, transparent in nature and/or capable of uniformdistribution.

One problem with using metal oxide particulate material in a liquidsubstance is the propensity for precipitation of the material from asolution over time, thus limiting the shelf life of the solution. Forexample, the use of commercially available fumed alumina or silicaresults in precipitation of the particulate metal oxide material afterabout one week in storage. Since fumed alumina or silica is of highviscosity, increased amounts of solvent are needed to attain a coatablecomposition. Accordingly, it is desired to provide an additive whichdoes not precipitate from solution and/or has a desirable viscosity.

U.S. Pat. No. 4,760,296 generally relates to the inclusion oforganosilicates or organoaluminates as the organo-metallic material ofchoice to achieve improved electrical stress endurance of an epoxy resinsystem. The '296 patent also relates to organoaluminates such asaluminum acetylacetonate and aluminum di-sec-butoxide acetoacetic esterchelate, which can be used to produce clear resins. However, theorganoaluminum compounds of the '296 patent are not suitable for avariety of resin systems. This is because they tend to (1) plasticizethe cured articles, (2) generate nonuniform distribution of theadditives in the cured articles, and/or (3) bleach out with aging. Thesame three disadvantages are associated with using fumed aluminum oxidein resin systems. Using fumed aluminum oxide also involves thedisadvantages that a clear solution cannot be formed and that theviscosity is undesirably high, further contributing to the creation ofvoids in the resulting coating thus rendering the coating susceptible tocorona attack.

Plasmas are useful for etching metals, semiconductors and dielectricsduring the processing of microelectronic materials such as wafers.Plasmas are also useful for cleaning, de-scumming, stripping andpassivating various surfaces of microelectronic materials. Plasma is anunstable mixture of positive ions, negative ions and free radicals.Examples of plasma include energized silicon tetrafluoride, Freons andoxygen. Accordingly, a plasma environment is a very severe andpotentially damaging environment, especially to polymeric materials. Inthe specific case of oxygen, monoatomic oxygen attack (oxygen plasma)can be very damaging to polymeric materials. This can be a problem if itis desired not to damage a polymeric substance in a plasma environment.It is therefore desirable to provide a polymeric substance which isplasma resistant.

These problems are minimized and/or eliminated by using the polymersmade with metal oxide sols of the present invention.

SUMMARY OF THE INVENTION

In one embodiment, the present invention relates to a polymer preparedfrom a mixture containing a polymerization material and apolycondensation product of a partially hydrolyzed chelated metal oxideprecursor.

In another embodiment, the present invention relates to a process formaking a polymer involving contacting a polymerization material with ametal oxide sol comprising a liquid and a polycondensation product of apartially hydrolyzed chelated metal oxide precursor to form a mixtureand at least one of polymerizing, curing, heating and cooling themixture of the polymerization material and the polycondensation product.

In yet another embodiment, the present invention relates to a prepolymermixture containing a polymerization material; and a metal oxide solcomprising a liquid and a polycondensation product of a partiallyhydrolyzed chelated metal oxide precursor.

The metal oxide sols are not particulate fillers which are added topolymers and physically trapped by the polymer network whereby thefillers are readily detectable in the resultant polymer system. Instead,the polycondensed partially hydrolyzed chelated metal oxide precursorsare chemically incorporated into the polymer network on a molecularlevel. It is believed that open functionalites (reactable functionalgroup of the multifunctional compound) of the metal oxide sol react withthe polymer during polymerization, curing, heating, and/or coolingthereby uniformly dispersing itself on a molecular level throughout theresultant polymer.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a polymer made with a metal oxide sol. Theinventive polymer may be made with a polymerization material and a metaloxide sol. The inventive polymer may include one or more additives suchas a cross-linking agent and an initiator. In one embodiment, thepolymerization material is a curable resin, and in particular, a lightor UV curable resin, such as acrylics, methacrylates and unsaturatedpolyesters. In another embodiment, the polymerization material is atleast one thermosetting resin which can be cured by means of externalenergy such as heat, light or electron beam to form at least a partiallythree dimensional cured product. In another embodiment, thepolymerization material is at least one thermoplastic resin. In yetanother embodiment, the polymerization material is a mixture containingat least one thermoplastic resin and at least one thermosetting resin.Although a number of categories of the polymerization materials aredescribed below, it will be understood that in some instances there isoverlap between any two or more given categories of polymerizationmaterials.

The term "hydrocarbyl" as used herein includes hydrocarbon as well assubstantially hydrocarbon groups. Substantially hydrocarbon describesgroups which contain heteroatom substituents which do not alter thepredominantly hydrocarbon nature of the group. Examples of hydrocarbylgroups include hydrocarbon substituents, i.e., aliphatic (e.g., alkyl oralkenyl) and substituted aliphatic substituents, alicyclic (e.g.,cycloalkyl, cycloalkenyl) substituents, aromatic-, aliphatic- andalicyclic-substituted aromatic substituents. Heteroatoms include, by wayof example, nitrogen, oxygen and sulfur.

The polymerization material is any material capable of forming apre-polymer material, a partially polymerized material or a polymer. Thepolymerization material may be monomers, a B-staged polymer, or apolymer. In one embodiment, the polymerization material is at least oneof an acrylic resin, an unsaturated polyester resin, a saturatedpolyester resin, an alkyd resin, a vinyl ester resin, a polyurethaneresin, an epoxy resin, a phenol resin, an urea-aldehyde resin, apolyvinyl aromatic, a maleimide resin, a polyvinyl halide resin, apolyolefin, a polyorganosiloxane, an amino resin, a polyamide, apolyimide, a polyetherimide, a polyphenylene sulfide resin, an aromaticpolysulfone, a polyamideimide, a polyesterimide, a polyesteramideimide,a polyvinyl acetal, a fluorinated polymer, a polycarbonate and the like.

Suitable polymerization materials include acrylic resins. Examples ofacrylic monomers include monoacrylics, diacrylics, triacrylics,tetraacrylics, pentacrylics, etc. Acrylic resins may be represented byFormula (I):

     (R.sup.1).sub.2 C═C(R.sup.1)COO!.sub.n R.sup.2        (I)

where each R¹ is independently selected from hydrogen and a monovalenthydrocarbyl group of 1 to about 13 carbon atoms, R² is hydrogen or amono- or polyvalent organic group of 1 to about 13 carbon atoms, and nis an integer having a value of 1 to about 4.

Examples of monoacrylates include isobornylacrylate,isobornylmethacrylate, ethoxyethoxyethyl acrylate,2-carboxyethylacrylate, ethylhexylacrylate, 2-hydroxyethylacrylate,2-phenoxylethylacrylate, 2-phenoxyethylmethacrylate,2-ethylbutylmethacrylate, 9-anthracenylmethyl methacrylate,4-chlorophenylacrylate, cyclohexylacrylate, dicyclopentenyloxyethylacrylate, 2-(N,N-diethylamino)ethyl methacrylate, dimethylaminoeopentylacrylate, caprolactone 2-(methacryloxy)ethylester, andfurfurylmethacrylate, poly(ethylene glycol)methacrylate, acrylic acidand poly(propylene glycol)methacrylate.

Examples of suitable diacrylates include2,2-bis(4-methacryloxyphenyl)propane, 1,2-butanediol diacrylate,1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate,1,4-cyclohexanediol dimethacrylate, 1,10-decanediol dimethacrylate,diethylene glycol diacrylate, dipropylene glycol diacrylate,dimethylpropanediol dimethacrylate, triethylene glycol dimethacrylate,tetraethylene glycol dimethacrylate, 1,6-hexanediol diacrylate,neopentyl glycol diacrylate, polyethylene glycol dimethacrylate,tripropylene glycol diacrylate, 2,2-bis4-(2-acryloxyethoxy)phenyl!propane, 2,2-bis4-(2-hydroxy-3-methacryloxypropoxy)phenyl!propane,bis(2-methacryloxyethyl)N, N'-1,9-nonylene biscarbamate,1,4-cycloheanedimethanol dimethacrylate, and diacrylic urethaneoligomers (reaction products of isocyanate terminate polyol and2-hydroethylacrylate).

Examples of triacrylates include tris(2-hydroxyethyl)isocyanuratetrimethacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate,trimethylolpropane trimethacrylate, trimethylolpropane triacrylate andpentaerythritol triacrylate. Examples of tetracrylates includepentaerythritol tetraacrylate, di-trimethylopropane tetraacrylate, andethoxylated pentaerythritol tetraacrylate. Examples of pentaacrylatesinclude dipentaerythritol pentaacrylate and pentaacrylate ester.

Acrylic polymerization materials also include another curablealiphatically unsaturated organic compound, such as an acrylamiderepresented by Formula (II):

     (R.sup.1).sub.2 C═C(R.sup.1)CON(R.sup.1).sub.2 !.sub.n R.sup.2 (II)

wherein R¹ and R² are as previously defined in Formula (I), and n is aninteger having a value of 1 to about 4; and unsaturated polyesters,which are condensation products of unsaturated dicarboxylic acids anddiols, and vinyl compounds, or compounds having a terminal double bond.In one embodiment, these materials are co-cured with the acryliccomponent by free radical technique. Examples of vinyl compounds includeN-vinylpyrrollidone, styrene, vinyl naphthalene and vinylphtalimide.Polyacrylamides (including poly(meth)acrylamide derivatives) arecommercially available. Some of the particular (meth)acrylamidederivatives useful in the present invention include N-alkyl- orN-alkylene-substituted or unsubstituted (meth)acrylamides. Specificexamples thereof are acrylamide, methacrylamide, N-methacrylamide,N-methylmethacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide,N,N-dimethylmethacrylamide, N,N-diethylacrylamide,N-ethylmethacrylamide, N-methyl-N-ethylacrylamide,N-isopropylacrylamide, N-n-propylacrylamide, N-isopropylmethacrylamide,N-n-propylmethacrylamide, N-acryloyloylpyrrolidine,N-methacryloylpyrrolidine, N-acryloylpiperidine,N-methacryloylpiperidine, N-acryloylhexahydroazepine,N-acryloylmorpholine and N-mathacryloylmorpholine.

The acrylic polymerization materials, as well as other resin systemsdescribed below, may also contain a photosentisizing amount of aphotoinitiator or a combination of photoinitiators, i.e., an amounteffective to effect the photocure of the composition in a non-oxidizingatmosphere, for example nitrogen, by absorbing the light energy, whetherUV or visible, and generating radicals. Generally, the photoinitiator(s)is included in the acrylic resin in an amount of from about 0.01% toabout 8.0% by weight, and preferably from about 0.1% to about 5.0% byweight of the curable resin. For example, some suitable unimolecularphotoinitiators, which absorb light and decompose to generate radicals,include 2,2-dimethoxy-2-phenylacetophenone,2-methoxy-2-phenylacetophenone, 2-dimethylamino-2-benzyl-1(4-morpholiniphenyl)-buten-1 -one anddiphenyl-2,4,6-trimethlbenzoylphosphine oxide.

Bimolecular photoinitiators, where photoabsorbing compounds such asketones react with electron donating compounds such as amines togenerate radicals, include combinations of ketones and amines. Examplesof such ketones are benzophenone, acetophenone,2-isopropylthiothanthone, xanthone, benzyl, camphorquinone and coumarinderivatives. Examples of the amines include 2-(dimethylamino)ethanol andmethyl p-(dimethylamino)benzoate.

In one embodiment, a cross-linking agent is used as part of thepolymerization material to achieve specific properties in the resultinginventive polymer, i.e., softness, high temperature performance, etc.Suitable cross-linking agents according to this standard includedi-functional and tri-functional acrylics, such as bisphenol-Adimethacrylate, tetra-functional acrylics, and di-pentaacrylates, suchas dipentaerythretol pentaacrylate.

Other suitable polymerization materials include unsaturated andsaturated polyester resins including alkyd resins. The unsaturatedpolyesters may be condensation polymers derived by the condensation ofunsaturated polybasic acids and anhydrides, such as dibasic acids oranhydrides, with polyols, such as dihydroxy or trihydroxy compounds. Thepolyesters may include in the polymeric chain, varying proportions ofother saturated or aromatic dibasic acids and anhydrides which are notsubject to cross-linking. The particular non-cross-linking componentsand their properties will depend upon the desired properties of thefinal products.

Examples of unsaturated polybasic acids or anhydrides which may beutilized in the formation of the polyester resins include maleic acid,fumaric acid, itaconic acid, tetrahydrophthalic acid, or the anhydridesof any of the foregoing. Examples of saturated aliphatic polycarboxylicacids include adipic and succinic acids, and examples of aromaticdicarboxylic acids include phthalic acid, isophthalic acid, terephthalicacid and halogenated derivatives such as tetrachlorophthalic acid andanhydride.

Examples of polyols include dihydroxy and trihydroxy compounds which inturn include ethylene glycol, propylene glycol, 1,3-propanediol,1,2-butanediol, 1,3-butanediol, 1,4-butanediol, diethylene glycol,dipropylene glycol, glycerol, neopentyl glycol, and reaction products ofalkylene oxides with, for example, 2,2'-bis(4-hydroxyphenylene)propane(a bisphenol A).

The unsaturated polyesters are prepared by reacting the one or moreunsaturated polybasic acids or anhydrides with the polyols (di- ortri-hydroxy compounds) in approximately equal proportions. Examples ofsuch polyesters include polyesters prepared from: maleic anhydride andpropylene glycol (1:1 molar ratio); isophthalic acid, maleic anhydrideand propylene glycol (1:2:3 and 1:1:2 molar ratios); and adipic acid,maleic anhydride and propylene glycol (1:2:3 molar ratio). A widevariety of polyester resins that can be used are commercially available.

Suitable polymerization materials include vinyl ester resins. The vinylester resins that can be used are the reaction products of epoxy resinsand a monofunctional ethylenically unsaturated carboxylic acids. Theymay be represented by Formula (III): ##STR1## where R³ is H or CH₃, R⁴is an epoxy resin, and m is about 2 to about 3, examples of the latterincluding epoxylated bisphenol A-epichlorohydrin and epoxylatedphenol-formaldehyde novolac. These resins can be made by reacting anepoxy resin with an ethylenically unsaturated carboxylic acid. The epoxyresins that can be used include diglycidyl ether of bisphenol A andhigher homologous thereof, the diglycidyl ether of tetrabromobisphenolA, epoxylated phenol-formaldehyde novolac, and polypropylene oxidediepoxide. The acids that can be used include acrylic and methacrylicacid. The acid-epoxide reaction can be catalyzed by tertiary amines,phosphines, alkali metal salts, or onium salts.

In one embodiment, the unsaturated polyester or vinyl ester is providedin a monomeric unsaturated polymerizable material. The monomericunsaturated polymerizable material is characterized by a terminalethylene group. In one embodiment, the terminal ethylene group isattached to an electronegative group such as the phenyl group as instyrene, halogen as in vinyl chloride, an acetoxy group as in vinylacetate or a carbethoxy group as in ethyl acrylate. Examples of themonomeric unsaturated polymerizable materials include styrene,alpha-methyl styrene, chloro styrene, vinyl toluene, divinyl benzene,diallylphthalate, methyl methacrylate, and mixtures of two or morethereof.

An example of an unsaturated polyester and monomeric unsaturatedpolymerizable material solution that can be used is available fromReichhold Chemicals under Product Code 7568-44-3; this material isidentified by the manufacturer as having an unsaturated polyester resincontent of about 60% by weight and a styrene monomer content of about35% by weight. Other examples include an unsaturated polyester resinbased on propylene glycol and maleic anhydride and styrene monomer(31-36% monomer) mixture from Reichhold Chemicals under Product Code31615-20; and a mixture of styrene monomer (26-32% by weight) andpolyester resin from Owens-Corning Fiberglas as product E-903.

Suitable polymerization materials include polyurethanes. Polyurethanescan be prepared by reacting polyfunctional hydroxy compounds, such asglycols, polyols and hydroxy-terminated polyesters and polyethers, withpolyfunctional aliphatic or aromatic isocyanates. Aliphatic or aromaticpolyurethanes can be utilized.

Polyurethanes include isocyanate-terminated polyurethanes. Theisocyanate-terminated polyurethane polymers are also referred to in theart as "prepolymers," and these polymers may be formed by the reactionof selected polyols having an average molecular weight of from about 200to about 2000 with a stoichiometric excess of an organic polyisocyanate.Such prepolymers are capable of chain extension and crosslinking(commonly called curing) with water or other chain-extending agents.

Any organic compound containing at least two active hydrogen atoms maybe reacted with the stoichiometric excess of organic polyisocyanate toform an isocyanate-terminated prepolymer which is then capable ofmolecular weight increase by curing as described above. The prepolymersmay have a free isocyanate content of from about 5% to about 20% byweight based on the prepolymer content.

Any of a wide variety of polyisocyanates can be employed in theformation of the polyurethane prepolymers useful in the invention.Diisocyanates are preferred, but minor amounts of other polyisocyanatescan be included. The isocyanates may be aliphatic, aromatic or mixedaliphatic-aromatic isocyanates. The diisocyanates generally have fromabout 6 to about 40 carbon atoms, and more often from about 8 to about20 carbon atoms in the hydrocarbon group.

The polyisocyanate can be saturated, unsaturated, monomeric orpolymeric. Illustrative examples of polyisocyanates which can be usedinclude: 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; m-phenylenediisocyanate; p-phenylene diisocyanate; 1,5-naphthalene diisocyanate;4,4'-diphenyl ether diisocyanate; 4,4',4"-triphenylmethanetriisocyanate; 2,4,4'-triisocyanatodiphenylmethane; 2,2',4-triisocyanatodiphenyl; 4,4'-diphenylmethane diisocyanate; 4,4'-benzophenonediisocyanate; 2,2-bis(4-isocyanatophenyl)propane; 1 ,4-naphthalenediisocyanate; 4-methoxy-1,3-phenylene diisocyanate;4-chloro-1,3-phenylenediisocyanate; 4-bromo-1,3-phenylene diisocyanate;4-ethoxy-1,3-phenylene diisocyanate; 2,4'-diisocyanatodiphenyl ether;4,4'-diisocyanatodiphenyl; 9,10-anthracene diisocyanate;4,6-dimethyl-1,3-phenylene diisocyanate; 4,4'-diisocyanatodibenzyl;3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane;3,3'-dimethyl-4,4'-diisocyanatodiphenyl;3,3'-dimethoxy-4,4'-diisocyanatodiphenyl; 1,8-naphthalene diisocyanate;2,4,6-toluene triisocyanate; 2,4,4'-triisocyanatodiphenyl ether;diphenylmethane diisocyanate available under the trademarks Mondur andPapi, having a functionality of 2.1 to 2.7; 1,3-xylene 4,6-diisocyanate;aromatic isocyanate-terminated polyurethanes; aromaticisocyanate-terminated prepolymers of polyesters; 1,6-hexamethylenediisocyanate; ethylene diisocyanate; propylene 1,2-diisocyanate;butylene 1,2-diisocyanate; butylene 2,3-diisocyanate; pentamethylenediisocyanate; cyclopentylene 1,3-diisocyanate; cyclohexylene1,2-diisocyanate; cyclohexylene 1,3-diisocyanate; cyclohexylene1,4-diisocyanate; 1-isocyanato-3-isocyanatomethyl-3,3,5-trimethylcyclohexane; methylcyclohexyl diisocyanate; 2,4,4-trimethylhexamethylenediisocyanate; 1,10-decamethylene diisocyanate; diisocyanato dicyclohexylmethane; 1,5-diisocyanato-2,2-dimethyl pentane; hydrogenated4,4'-diphenylmethane diisocyanate; hydrogenated toluene diisocyanate;(OCNCH₂ CH₂)₂ S; (OCNCH₂ CH₂ CH₂)₂ O; OCNCH₂ CH₂ CH₂ CH(OCH₃)CH₂ CH₂NCO; and OCNCH₂ CH₂ CH₂ O(CH₂)₄ OCH₂ CH₂ CH₂ NCO.

Examples of commercially available polyisocyanates that can be usedinclude Lupranate MP102 (a product of BASF identified as solvent-freeurethane-modified diphenylmethane diisocyanate), and Rubinate 1780 (aproduct of ICI identified as polymeric methylene diphenyl diisocyanate).

The polyols may be aliphatic, cycloaliphatic, aromatic or mixedstructures. These polyols are diols, including ether diols, triolsincluding ether triols or mixtures thereof. Other polyols having greaterthan three hydroxy groups may also be used in conjunction with the diolsand/or triols. The structure of the polyol is usually hydrocarbon innature, but other substituents may be incorporated in the hydrocarbonmoiety to effect changes in the properties of the resulting prepolymer.The molecular weights of these polyols average up to about 2000 or morebut those of 300 to about 1000 average molecular weight are preferred.Examples of polyols useful in the present invention include those listedin connection with the polyesters, and preferable polyols includepolyoxyethylene glycols, polyoxypropylene glycols, polyoxybutyleneglycols, etc. Useful monomeric glycols include ethylene glycol,propylene glycol, butene diols, 1,6-hexamethylene glycol, etc. Examplesof triols include trimethylol propane, trimethylol ethane, glycerol,1,2,6-hexane triol, etc.

Hydroxy-terminated polyester materials also are useful hydroxyreactants. Such hydroxy-terminated polyester materials can be preparedby the reaction of one or more of the polyhydroxy materials describedabove with one or more aliphatic, including cycloaliphatic, or aromaticpolycarboxylic acids or esters, and such polyesters can often havehydroxyl values in the range of from about 25 to about 150. Examples ofsuch acids include phthalic acid, adipic acid, sebacic acid, etc.

In one embodiment, organo tin compounds, are useful catalysts for thehydroxyl/isocyanate reaction. Examples of such organo tin compoundsinclude dibutyl tin dilaurate, stannous octoate, dibutyl tin (IV)diacetate and dibutyl tin (IV) oxide. An example of a commerciallyavailable organo tin compound that can be used is Fastcat 4202, which isa product of M&T Chemicals identified as dibutyl tin dilaurate. Otheruseful catalysts include tertiary aliphatic and alicyclic amines such astriethylamine, triethanolamine, tri-n-butylamine, etc. Mixtures ofcatalysts can also be employed.

The polymerization initiator may be a free radical initiator capable ofgenerating free radicals that can initiate cross-linking or curing. Inone embodiment, the polymerization initiators are chosen from materialswhich contain either a peroxide group or an azo group. Examples ofuseful peroxide compounds include t-butyl perbenzoate, t-butylperoctoate, benzoyl peroxide, t-butyl hydroperoxide, succinic acidperoxide, cumene hydroperoxide and dibenzoyl peroxide. Examples ofuseful azo compounds include azobisisobutyronitrile andt-butylazoisobutyronitrile. Generally, the concentration of an initiatorin the inventive composition is from about 0.1% to about 5% by weight,and in one embodiment about 0.2% to about 1% by weight, based on thetotal weight of the inventive composition.

The isocyanate-terminated polyurethanes can be prepared by thesimultaneous reaction of an excess organic polyisocyanate and polyol, orby reacting part or all of a polyol prior to reaction of the remainingamount of the material with the isocyanate. Generally, it is preferredto add the polyisocyanate to an essentially inert organic solventsolution of polyol from which all moisture has been removed. Thereaction between the polyol and the organic polyisocyanate generally iscompleted in about 1 to 3 hours in the absence of a catalyst. When acatalyst is used, a reaction period of about 10 minutes to about 3 hoursis sufficient. General examples of polyurethanes include those under thetrade designation Estane from BFGoodrich, Pellethane from Dow Plastics,Texin and Desmopan from Bayer and Carbon-Flex from Cabot.

Suitable polymerizable materials include epoxy resins. Epoxy resinsinclude resins comprised of monomers, oligomers, and polymers containingone or more oxirane rings. The oxirane ring reacts by ring opening,which is not considered a condensation reaction, but rather an openingof the oxirane ring by initiated by acidic or basic catalysts. Epoxyresins may vary greatly in the nature of their backbones and substituentgroups. A wide variety of such resins are available commercially. Suchresins have either a mixed aliphatic-aromatic or an exclusivelynon-benzeneoid (i.e., aliphatic or cycloaliphatic) molecular structure.Representative examples of acceptable substituent groups includehalogens, ester groups, ether groups, sulfonate groups, siloxane groups,nitro groups, and phosphate groups. Mixtures of various epoxy-containingmaterials may be used in the compositions of the invention.

The mixed aliphatic-aromatic epoxy resins which are useful with thepresent invention are prepared by the well-known reaction of abis(hydroxy-aromatic) alkane or a tetrakis-(hydroxyaromatic)-alkane witha halogen-substituted aliphatic epoxide in the presence of a base suchas, e.g., sodium hydroxide or potassium hydroxide. Under theseconditions, hydrogen halide is first eliminated and the aliphaticepoxide group is coupled to the aromatic nucleus via an ether linkage.Then the epoxide groups condense with the hydroxyl groups to formpolymeric molecules which vary in size according to the relativeproportions of reactants and the reaction time.

In lieu of the epichlorohydrin, one can use halogen-substitutedaliphatic epoxides containing about 4 or more carbon atoms, generallyabout 4 to about 20 carbon atoms. In general, it is preferred to use achlorine-substituted terminal alkylene oxide (terminal denoting that theepoxide group is on the end of the alkyl chain) and a particularpreference is expressed for epichlorohydrin by reason of its commercialavailability and excellence in forming epoxy resins useful for thepurpose of this invention. If desired, the halogen-substituted aliphaticepoxide may also contain substituents such as, e.g., hydroxy keto,nitro, nitroso, ether, sulfide, carboalkoxy, etc.

Similarly, in lieu of the 2,2-bis-(p-hydroxyphenyl)-propane, one can usebis-(hydroxyaromatic) alkanes containing about 16 or more carbon atoms,generally about 16 to about 30 carbon atoms such as, e.g.,2,2-bis-(1-hydroxy-4-naphthyl)propane; 2,2-bis(o-hydroxyphenyl)propane;2,2-bis-(p-hydroxyphenyl) butane, 3,3-bis-(p-hydroxyphenyl)hexane;2-(p-hydroxyphenyl)-4-(1-hydroxy-4-naphthyl) octane,5-5-bis-(p-hydroxy-o-methylphenyl)-decane, bis-(p-hydroxyphenyl)methane, 2,2-bis-(p-hydroxy-o-isopropylphenyl)propane,2,2-bis-(o,p-dihydroxyphenyl)propane,2-(p-hydroxyphenyl)-5-(o-hydroxyphenyl)hexadecane, and the like. Ifdesired, the bis-(hydroxyaromatic)alkane may contain substituents suchas, e.g., halogen, nitro, nitroso, ether, sulfide, carboalkoxy, etc. Ingeneral, it is preferred to use a bis-(p-hydroxyphenyl)alkane sincecompounds of this type are readily available from the well-knowncondensation of phenols with aliphatic ketones or aldehydes in thepresence of a dehydrating agent such as sulfuric acid. Particularlypreferred is 2,2-bis-(p-hydroxyphenyl)propane, which is availablecommercially as "Bisphenol A".

Epoxy resins are available from a wide variety of commercial sources.One group is known by the general trade designation "Epon" resins andare available from Shell Chemical Co. For example, "Epon 820" is anepoxy resin having an average molecular weight of about 380 and isprepared from 2,2-bis-(p-hydroxyphenyl)propane and epichlorohydrin.Similarly, "Epon 1031" is an epoxy resin having an average molecularweight of about 616 and is prepared from epichlorohydrin and symmetricaltetrakis-(p-hydroxyphenyl)ethane. "Epon 828" has a molecular weight of350-400 and an epoxide equivalent of about 175-210. Epoxy resins such asAraldite 6010, manufactured by Ciba-Geigy can also be utilized. Theseepoxy resins are of the glycidyl-type epoxide, and are preferablydiglycidyl ethers of bis-phenol A which are derived from bisphenol andepichlorohydrin.

Another group of commercially available epoxy resins are identifiedunder the general trade designation EPI-REZ (Celanese Resins, a Divisionof Celanese Coatings Company). For example, EPI-REZ 510 and EPI-REZ 509are commercial grades of the diglycidyl ether of Bisphenol A differingslightly in viscosity and epoxide equivalent.

Another group of epoxy resins are available from Furane Plastics Inc.,Los Angeles, Calif. under the general trade designations EPIBOND andEPOCAST. For example, EPIBOND 100A is a one component epoxy resin powderavailable from Furane which is curable to a hard resin in the absence ofany hardener.

Liquid forms of epoxy resin are also useful. These liquid forms normallycomprise very viscous liquids requiring some degree of heating to permitwithdrawal from storage containers. Certain "D.E.R." and "D.E.W." resinsobtainable from Dow Chemical Company and "Epotuf" liquid epoxy resinsobtainable from Reichhold Chemicals Inc. are examples of such resinspreferred for employment in accordance with the invention. An example ofan "Epotuf" liquid epoxy resin in the undiluted medium high viscosity#37-140 having an epoxide equivalent weight of 180-195, a viscosity(ASTM D445) of 11,000-14,000 cps at 525° C., and a Gardner Color Maximumof 3. This is a standard general purpose epoxy resin.

In some embodiments of the invention the epoxy resins may be"solubilized" by neutralization with a basic compound such as an organicamine. Examples of amines include amines and hydroxyamines includingdiethylamine, triethylamine, triethanolamine, dimethylethanolamine, etc.Epoxy resins also include polyamide modified epoxy resins, such as AF-42from Minnesota Mining and Manufacturing Co.

Additional examples of the epoxy resins derived from amines includetetraglycidyidiaminodiphenylmethane, triglycidyl-p-aminophenol,triglycidyl-m-aminophenol and triglycidylaminocresol and their isomers,examples of the epoxy resins derived from phenols include bisphenol Aepoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins,phenol-novolak epoxy resins, cresol-novolak epoxy resins and resorcinolepoxy resins, and examples of the epoxy resins whose precursors arecompounds having a carbon-carbon double bond are alicyclic epoxy resins.Moreover, brominated epoxy resins prepared by brominating these epoxyresins can be used, but the present invention is not restricted to theuse of these compounds. Furthermore, mixtures of two or more of theepoxy resins can be used and monoepoxy compounds can also beincorporated.

Generally, epoxy resins for use in the invention are compositionscomprising glycidyl ether monomers. Representative examples of these arethe glycidyl ethers of polyhydric phenols obtained by reacting apolyhydric phenol with an excess of chlorohydric, such asepichlorohydrin. Specific examples of epoxy resins include 2,2-bis4-(2,3-epoxypropoxy)phenyl!propane(diglycidyl ether of bisphenol A) andcommercially available materials under the trade designation "Epon828F", "Epon 1004F" and "Epon 1001F" available from Shell Chemical Co.,"DER-331", DER-332" and "DER-334" available from the Dow Chemical Co.Preferred is the diglycidyl ether of bisphenol A. A composition meetingthis description is available under the trade designation "CMD 35201"available from Rhone Poulenc, Inc., Louisville, Ky. Other suitable epoxyresins include glycidyl ethers of phenol formaldehyde novolak resins(e.g., "DEN-431" and "DEN-438" available from the Dow Chemical Co.), andresorcinol digylcidyl ether. Additional examples of epoxides aredescribed in U.S. Pat. No. 3,018,262, incorporated herein by reference.

As noted, epoxy resins generally require curing agents which react withthe oxirane groups of the epoxy resin to form cross-linked binders.Curing agents useful in the invention are typically and preferablyselected from amides and imidazoles. One useful amide is the polyamideknown under the trade designation "VERSAMID 125", commercially availableform Air Products, Allentown, Pa., which is a 100 percents solidsversion of 2-ethyl-4-methyl imidazole.

Suitable polymerizable materials include phenol resins and urea-aldehyderesins. Phenolic resins and urea-aldehyde resins useful in the inventionas thermosetting resins include those disclosed in U.S. Pat. No.5,178,646, columns 15-17, which is incorporated herein by reference.These resins comprise the reaction product of an aldehyde and anon-aldehyde such as a urea compound or a phenolic compound. The generalterm "phenolic" includes phenol-formaldehyde resins as well as resinscomprising other phenol-derived compounds and aldehydes. The phenolicresins are any of the several types of synthetic thermosetting resinsmade by reacting a phenol, cresol, zylenol, xylenol, p-t-butyl phenol,p-phenyl phenol, bisphenol and resorcinol with an aldehyde. Examples ofthe aldehydes include formaldehyde, acetaldehyde and furfural.

Resole phenolic resins can be catalyzed by alkaline catalysts, and themolar ratio of formaldehyde to phenol is greater than or equal to one,typically between 1.0 to 3.0, thus presenting pendant methylol groups.Alkaline catalysts suitable for catalyzing the reactions betweenaldehyde and phenolic components of resole phenolic resins includesodium hydroxide, barium hydroxide, potassium hydroxide, calciumhydroxide, organic amines, and sodium carbonate, all as solutions of thecatalyst dissolved in water. A general discussion of phenolic resins andtheir manufacture is given in Kirk-Othmer, Encyclopedia of ChemicalTechnology, 3^(rd) Ed., John Wiley & Son, 1981, N.Y., Vol. 17, p.349-et.seq., which is incorporated herein by reference.

Examples of commercially available phenolic resins useful in theinvention include those known by the trade names "Vacrum" (from DurezDivision of Occidental Chemical Corp.), "Aerofene" (from AshlandChemical Co.), "Valite" from Lockport Thermosets and "Bakelite" fromUnion Carbide. A standard, 70% solids (1.96:1.0 molar ratio offormaldehyde to phenol) phenolic resin having a 2 weight percent KOH perweight of phenol is available from Nests Resins Canada, Mississauga,Ontario, Canada.

Suitable polymerizable materials include polyvinyl aromatics. Polyvinylaromatics are commercially available. Examples of polyvinyl aromaticsinclude polystyrene, copolymers and terpolymers of one or more of thefollowing polystyrene, polystyreneacrylonitrile,polystyrenebutadieneacrylonitrile, vinyltoluene, α-methylstyrene,chloromethylstyrene. Specific aromatic resins include those known underthe trade designations Dylite M-77A, M-77B, M-77C and 33mA-B-C fromArco, Styropor BF 122, 322 and 422 from BASF, 3486, 4486, 254, 454 and554 from Huntsman, MA500, MB500, MB950 and MBC 590 from StyroChem,"Piccolastic A75", "Picco 6100", and "Picco 5140" all solids at roomtemperature and all commercially available from Hercules, Inc.,Wilmington, Del. "Piccolastic A75" is a low molecular weightthermoplastic polystyrene resin, and "Picco 6100" and "Picco 5140" arelow molecular weight, nonpolar, aromatic thermoplastic polymerizedresins derived from C₇ to C₉ monomers.

Other aromatic resins include those known under the trade designations"Tacolyn 1085", "Piccotex LC-55WK" and "Piccotac 95-55WK" which areaqueous, 55 percent solids, organic solvent-free, resin dispersionscommercially available from Hercules Inc., Wilmington, Del. "PiccotexLC-55WK" is an anionic dispersion of a polymerized resin known under thetrade designation "Piccotex LC" (also from Hercules) derived fromcopolymerizing vinyl toluene and alpha-methyl styrene. "Piccotac95-55WK" is a dispersion of a polymerized aliphatic hydrocarbon resinknown under the trade designation "Piccotac 95", also from Hercules.

Suitable polymerizable materials include maleimide resins. Maleimideresins may be derived from those compounds which contain 2 or moremaleimide groups, on average, in a molecule and may be represented byFormula (IV): ##STR2## (wherein X is an alkylene group, a cycloalkylenegroup, a divalent hydrocarbyl group such as monocyclic or polycyclicarylene group or a divalent hydrocarbyl group bound with a divalentatomic group such as --CH₂ --, --CO--, --SO₂ --, --O--, --C(CH₃)₂ --,--CONH) or from maleimide compounds obtained by reacting maleicanhydride with a mixed polyamine. As maleimide compounds of this type,there are, for example, N,N'-phenylenebismaleimide,N,N'-hexamethylenebismaleimide, N,N'-oxy-di-p-phenylenebismaleimide,N,N'-4,4'-benzophenonebismaleimide, N,N'-diphenylsulfonebismaleimide,N,N'-(3,3'-dimethyl)-methylene-di-p-phenylenebismaleimide,N,N'-4,4'-dicyclohexylmethanebismaleimide, N,N'-m(orp)-xylenebismaleimide,N,N'-(3,3'-dimethyl)methylene-di-p-phenylenebismaleimide,N,N'-m-tolylenedimaleimide, bismaleimide of bis(aminophenoxy) benzeneand a reaction product of maleic anhydride with a mixed polyamine whichis a reaction product of aniline and formaline, but the presentinvention is not restricted to the use of these compounds. Moreover,these maleimide compounds can be used as a mixture of two or morecompounds and monomaleimide compounds such as N-allymaleimide,N-propylmaleimide, N-hexylmaleimide and N-phenylmaleimide can beincorporated.

Maleimide resins are preferably used in combination with a curing agent.As the curing agent, and compounds which has an active group beingreactive with the maleimide group can be used. Particularly suitable arethose compounds which have an amino group, an alkenyl group exemplifiedby an allyl group, a benzocyclobutene group, an allyl-nadicimide group,an isocyanate group, a cyanate group or an epoxy group. For example, asa curing agent having an amino group, diamino-diphenylmethane is arepresentative compound and as a curing agent having an alkenyl group,o,o'-diallyl-bisphenol A and bis(propenylphenoxy) sulfone are cited.

Suitable polymerizable materials include polyvinylhalides. Inparticular, homo and copolymers of polyvinylchloride, polyvinylfluorideand polyvinylidene fluoride and difluoride may be used. Thepolyvinylchloride resins (sometimes referred to herein as PVC resins)which are suitable for use in the present invention are well known andare either homopolymers of vinyl chloride or copolymers of vinylchloride with a minor amount by weight of one or moreethylenically-unsaturated comonomers which are copolymerizable with thevinyl chloride. Examples of these ethylenically-unsaturated comonomersinclude vinyl halides such as vinyl fluoride and vinyl bromide;alpha-olefins such as ethylene, propylene and butylene; vinyl esterssuch as vinyl acetate, vinyl propionate, vinyl butyrate and vinylhexanoate, or partially hydrolyzed products thereof such as vinylalcohol; vinyl ethers such as methyl vinyl ether, propyl vinyl ether andbutyl vinyl ether; acrylic esters such as methyl acrylate, ethylacrylate, methyl methacrylate and butyl methacrylate and other monomerssuch as acrylonitrile, vinylidene chloride and dibutyl maleate. Suchresins are generally known any many are commercially available.

Examples of polyvinylchloride resins that are commercially availableinclude a number of those under the trade designation GEON® includingGEON® 92, a medium high molecular weight porous suspension PVC resin;GEON® 128, a high molecular weight dispersion grade polyvinylchlorideresin; and GEON® 11X 426FG, a medium molecular weight PVC resin. TheGEON® resins are available from the Geon Company. Preferred PVC resinsare UV light stabilized compositions. Examples of polyvinylidenefluoride resins include those under the trade designations Hylar fromAusimont and Kynar from Elf Altochem.

The PVC resins may contain significant amounts of plasticizers,generally, from about 10% to about 60% by weight of at least oneplasticizer. The plasticizers which are incorporated into the PVC resinsmay be any of the substances conventionally used to plasticize PVCresins. These are normally considered to fall into two classes: highmolecular weight or polymeric plasticizers (of molecular weight of about750 to 5000) and low molecular weight of monomeric plasticizers (ofmolecular weight of about 300 to 1000). The higher molecular weightplasticizers such as chain-stopped polypropylene glycol adipate orpoly(1,3-butane diol azolate) have lower volatility. More specificexamples of plasticizers include esters of dibasic organic acids orphosphoric acid, derivatives of castor oil, epoxidized vegetable oils,ethylene glycol derivatives, polyesters, chlorinated paraffin orchlorinated fatty acid esters.

Generally, the plasticizers utilized in the PVC resins are medium tohigh-molecular weight liquid di- and tri-esters of organic acids.Chlorinated polyethylene and ethylene-vinyl acetate resins are examplesof the plasticizers which have been referred to as solid plasticizers.These are generally polymers which alloy with the host resin and impartsome combination of increased flexibility and impact resistance.

Phthalate esters are the most commonly used class of plasticizers. Thesecompounds are used not only for PVC resins, but also for polyvinylacetate, polyolefins, polyurethanes, etc. However, the amount ofplasticizer utilized in the polyolefins and polyurethanes is much lessthan the amount used in PVC resins. A listing of commercially availableplasticizers is found in Modern Plastics Encyclopedia, 1993, pp.326-335.

The PVC resins may contain other materials normally used to providedesirable properties to the PVC resins. For example, the PVC resins mayalso contain: heat and light stabilizers, such as alkyl aryl phosphatesand 4,4'-butylidene-bis(6-t-butyl-m-cresol); lubricants; colorants suchas dyes and pigments; foaming agents, wetting agents; flame-retardants;antistatic agents; thickening agents and coupling agents.

Suitable polymerizable materials include polyolefins. Polyolefinsinclude polymer and copolymers of monoolefins having from 2 to about 20carbon atoms and more preferably from 2 to about 12 carbon atoms permolecule. Monoolefins useful for making polyolefins preferably contain aterminal olefin bond and these include ethylene, propylene, 1-butene,1-pentene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-octene, 1-decene and4-ethyl-1-hexene. Examples of such homopolymers include polyethylene(including low density, medium density, high density, linear low densityand ultralow density polyethylene), polypropylene (including lowdensity, high density and isotactic polypropylene), poly-1-butene,poly-3-methyl-1-butene and poly-4-methyl-1-pentene. The examples ofcopolymers within the above definition include copolymers of ethylenewith from about 1% to about 99% by weight of propylene, copolymers ofpropylene with about 1% to about 99% by weight of ethylene or 1-butene,etc. Polymers prepared from blends of copolymers or blends of copolymerswith homopolymers also are useful. These polymers are available from anumber of sources including Phillips, Shell, Himont and Exxon.

Suitable polymerizable materials include silicone polymers, such as apolyorganosiloxane. In a specific embodiment, the polyorganosiloxane isa polydimethylsiloxane. The polysiloxanes may be thermally cured orradiation cured. Generally, the thermally curable compositions compriseat least one polyorganosiloxane and at least one catalyst or curingagent for such polyorganosiloxane(s). Such compositions may also containat least one cure accelerator.

A wide variety of polyorganosiloxanes (commonly called silicones) can beused in the practice of the invention. Such polyorganosiloxanes are alsosometimes referred to as polymeric silicone resins, rubbers, oils orfluids. These compositions are well known and fully described in theliterature. These compositions are comprised essentially of siliconatoms connected to each other by oxygen atoms through silicon-oxygenlinkages, i.e., by Formula (V): ##STR3## wherein each R⁵ isindependently an organic group, generally an alkyl group. Variouspolyorganosiloxanes are commercially available in organic solvents invarious percent solids concentration. Exemplary of the silicone(polyorganosiloxane) materials which can be used in forming the siliconepolymers of the invention are those disclosed in U.S. Pat. Nos.2,258,218; 2,258,220; 2,258,222; 2,494,920; 3,432,333; and 3,518,325which are hereby incorporated by reference.

Suitable catalysts which can be employed in the curing of thepolyorganosiloxanes include various compounds containing metals such astin, lead, platinum, rhodium, etc. Generally, the catalysts are tin,platinum or rhodium compounds such as the dialkyl tin esters. Specificexamples of catalysts include: dibutyl tin diacetate, dibutyl tindi-ethylhexanoate, dihexyl tin di-2-ethyl hexanoate, ethyl tintrihexanoate, dibutyl tin dilaurate, octadecyl tin dilaurate, dibutyltin diacetate, tri-butyl tin acetate, dibutyl tin succinate, variouslead salts such as lead naphthenate and lead octoate, zinc octoate, zincstearate, iron octoate, various organic peroxides such as benzoylperoxide and 2,4-dichlorobenzoyl peroxide, and others well known in theart as curing agents or catalysts for polyorganosiloxanes. Metalcomplexes of platinum and rhodium are also useful. Amines and aminesderivatives such as diethylene triamine, triethylene tetramine andethanol amine, as well as amine precursors such as the isocyanatecompounds and amine-functional silanes such as gamma-aminopropyltriethoxy silane can also be used as curing catalysts. The amine saltsof carboxylic acids can also be used as curing agents.

Curing of the polyorganosiloxanes can take place at room temperaturedepending upon the particular silicone material used and the particularcuring agent or catalyst used in conjunction with the silicone material.Most curing agents or catalysts are capable of promoting relativelyrapid curing at moderate elevated temperatures. For the preferredpolyorganosiloxanes described herein, this temperature is in the rangeof about 160° F. to about 650° F. Once curing has been initiated andmaintained at an elevated temperature for a short period of time asdescribed herein, the curing can then advantageously be allowed toproceed by aging at reduced temperatures, e.g., at room temperatures ormoderately (25° F. to 50° F.) above room temperature. The choice oftemperature actually employed in the curing steps will depend upon anumber of factors such as the type of silicone coating material used andthe curing catalyst used with said silicone material.

Curable polyorganosiloxanes can be cured by ultraviolet or electron beamradiation with or without the assistance of a photoinitiator such asbenzophenone. One type of polyorganosiloxane contains acryloxy groups,methacryloxy groups, or mixtures thereof. A variety of acryloxy ormethacryloxy containing polyorganosiloxanes are known and can be used.In one embodiment, the polyorganosiloxane compounds containing acryloxyand/or methacryloxy groups which can be utilized may be presented- byFormula (VI):

     R.sub.n SiO.sub.4-n/2 !.sub.m                             (VI)

wherein each R is acryloxy, methacryloxy, an n-substituted monovalenthydrocarbyl group containing from 1 to about 20 carbon atoms or asubstituted monovalent hydrocarbyl group wherein the substituents areselected from the class consisting of chloro-, fluoro-, cyano-, amido-,nitro-, ureido-, isocyanato-, carbalkoxy-, hydroxy-, acryloxy-,methacryloxy-, etc.; n has an average value of about 1.8 to 2.2; and mhas an average value greater than 2, preferably greater than about 25,and more preferably, from about 100 to about 500; the polyorganosiloxanecontaining an average of at least one R group which contains an acryloxyor methacryloxy group, namely,

    CH.sub.2 ═C(X)C(O)--O--

wherein X is hydrogen or alkyl such as methyl. The substituentsrepresented by R in Formula (VI) include, for example, monovalentaliphatic groups such as methyl, ethyl, propyl, hexyl, etc.; monovalentcycloaliphatic groups such as cyclohexyl, cyclopentyl, etc.; aryl groupssuch as phenyl, methylphenyl, benzyl, etc.; alkenyl groups such asvinyl, allyl, 3-butenyl, etc. Examples of R groups which are substitutedhydrocarbon groups include pentachlorophenyl, aminomethyl,3-aminopropyl, etc.

Each acryloxy or methacryloxy group is attached to the siloxane backbonethrough a carbon-to-silicon bond or a carbon-oxygen-silicon bond. Moreoften, there are present an average of from about 2 to about 25, morepreferably from about 2 to about 10 of the R groups containing anacryloxy or methacryloxy group. Alternatively, the polyorganosiloxanecompounds containing acryloxy and/or methacryloxy groups useful in thepresent invention may be defined as containing from about 3% to about75% by weight of acryloxy or methacryloxy groups, more often from about3% to about 50% by weight of the acryloxy or methacryloxy groups.

Typically, the R groups in Formula (VI) have a structure as representedby Formula (VII):

    CH.sub.2 ═C(X)C(O)--O--R.sup.6 --                      (VII)

wherein R⁶ is a divalent hydrocarbyl group of from 1 to about 15 carbonatoms or an oxyalkylene group containing from 1 to about 4 carbon atomsin the alkylene moiety and X is as described above.

The siloxanes containing the acryloxy or methacryloxy groups of Formula(VII) can be prepared, for example, by reacting a siloxane containinghydroxyl groups or epoxy groups with acrylic acid or methacrylic acid.The siloxanes containing hydroxyl groups may be prepared by reacting areactive siloxane (e.g., containing halogen) with a polyhydroxy compoundsuch as ethylene glycol, propylene glycol, glycerol or pentaerythritol.

The polyorganosiloxanes described above may be linear or branched. Aswill be recognized by those skilled in the art, the polyorganosiloxanesof Formula (VII) will also have an appropriate number of end-cappingunits, R₃ S₁ O-- at the terminals of the molecule where R is aspreviously defined.

The disclosures of U.S. Pat. Nos. 3,878,263; 4,064,286; 4,301,268;4,306,050; 4,908,274; 4,963,438; 4,978,726; and 5,034,491 are herebyincorporated by reference for their disclosure of acrylate ormethacrylate containing polyorganosiloxanes and methods of preparingpolyorganosiloxanes containing acryloxy and/or methacryloxy groupsuseful in the present invention.

Polyorganosiloxanes containing acryloxy and/or methacryloxy groups areavailable commercially from, for example, Goldschmidt Chemical Corp.,Hopewell, Va. Goldschmidt's silicone acrylate series includedimethylpolysiloxanes available under the general trade designationTergo® RC, and more particularly, under designations such as RC 450, RC450N, RC 706, RC 707, RC 710, RC 720 and RC 726. Some of thesepolysiloxanes are of the type prepared by the reaction of acrylic acidor methacrylic acid with dimethylpolysiloxane containing hydroxyl groupsor epoxy groups.

In another embodiment, the curable silicone polymer comprises a mixtureof at least two classes of materials: (i) an organopolysiloxanecontaining acryloxy or methacryloxy groups described above, and (ii)acrylated or methacrylated organic polyhydroxy compounds or polyaminocompounds. Any acrylated and methacrylated organic polyhydroxy andpolyamino compounds can be used in combination with the above-describedpolysiloxanes.

The weight ratio of (i) organopolysiloxane to (ii) acrylated andmethacrylated polyhydroxy and polyamino compounds may vary over a widerange. Thus, a mixture may comprise from about 2% by weight up to about90% by weight of the polysiloxane and from about 10% to about 98% byweight of the acrylated or methacrylated polyhydroxy and/or polyaminocompounds. The silicone polymers preferably comprise a mixture of morethan one acrylated or methacrylated organic polyhydroxy compound orpolyamino compound. Such mixtures may comprise two or more derivativesderived from polyhydroxy compounds, two or more compounds derived frompolyamino compounds, mixtures of one or more compounds derived from apolyhydroxy compound and one or more compounds derived from a polyaminocompound. Thus, in one embodiment, the mixture comprises a mixture of(1) from about 40% to about 70% by weight of at least one acrylated ormethacrylated polyamine oligomer and (2) from about 30% to about 60% byweight of at least one acrylated or methacrylated polyhydroxy compoundas described above.

In yet another embodiment of the present invention, a portion of theacrylated or methacrylated compound may be replaced by a liquidmonoacrylate ester. For example, from about 1% to about 20% by weight ofthe polyacrylate in the above mixtures may be replaced by a liquidmonoacrylate ester to modify the properties of the curable siliconepolymers. The liquid monoacrylate esters generally are characterized bya low viscosity such as from 1 to about 50 cps at 25° C., and thesemonoacrylate compounds are useful to improve the fluidity. Examples ofsuch liquid monoacrylate esters include ethyl acrylate, butyl acrylate,2-ethylhexyl acrylate, allyl acrylate, n-amyl acrylate, benzyl acrylate,cyclohexyl acrylate, diethylaminoethyl acrylate, 2-ethoxyethyl acrylate,n-lauryl acrylate, n-octyl acrylate, octadecyl acrylate, etc., thecorresponding methacrylates and mixtures thereof.

The curable silicone polymers useful in the present invention optionallymay contain at least one photoinitiator. The amount of photoinitiatorincluded may range from about 0% to about 10%, more often from about0.5% to about 5% based on the total weight of the curable composition. Aphotoinitiator is incorporated when the polymer is to be cured byexposure to non-ionizing radiation such as ultraviolet light.Photoinitiators are not required when the curable silicone polymer iscured by electron beam radiation. Examples of photoinitiators which maybe used in combination with ultraviolet light includes, for example,benzyl ketals, benzoin ethers, acetophenone derivatives, ketoximeethers, benzophenone, benzo or thioxanthones, etc. Specific examples ofphotoinitiators include: 2,2-diethoxyacetophenone; 2- or 3- or4-bromoacetophenone; benzoin; benzophenone; benzoquinone;1-chloroanthroquinone; p-diacetyl-benzene; 9,10-dibromoanthracene;1,3-diphenyl-2-propanone; 1,4-naphthyl-phenyl ketone; 2,3-pentenedione;propiophenone; chlorothioxanthone; xanthone; and mixtures thereof.

Suitable polymerizable materials further include amino resins. The aminoresins (sometimes referred to as aminoplast resins or polyalkyleneamides) are nitrogen-rich polymers containing nitrogen in the aminoform, --NH₂. The starting amino-bearing material is usually reacted withan aldehyde (e.g., formaldehyde) to form a reactive monomer, which isthen polymerized to a thermosetting resin. Examples of amino-bearingmaterials include urea, melamine, copolymers of both with formaldehyde,thiourea, aniline, dicyanodiamide, toluene sulfonamide, benzoguanamine,ethylene urea and acrylamide. Preferred amino resins are themelamine-formaldehyde, melamine alkyl, and urea-formaldehyde resins.

Condensation products of other amines and amides can also be employed,for example, aldehyde condensates of triazines, diazines, triazoles,guanadines, guanamines and alkyl and aryl-substituted derivatives ofsuch compounds including alkyl- and aryl-substituted ureas and alkyl-and aryl-substituted melamines. Some examples of such compounds areN,N'-dimethylurea, benzourea, dicyandiamide,2-chloro-4,6-diamino-1,3,5-triazine and 3,5-diaminotriazole. Otherexamples of melamine and urea-based cross-linking resins includealkylated melamine resins including methylated melamine-formaldehyderesins such as hexamethoxymethyl melamine, alkoxymethyl melamines andureas in which the alkoxy groups have 1 to about 4 carbon atoms such asmethoxy, ethoxy, propoxy, or butoxymethyl melamines and dialkoxymethylureas; alkylol melamines and ureas such as hexamethylol melamine anddimethylol urea. The aminoplast cross-linking resins may be combinedwith another thermosetting resin such as an alkyl resin, a polyesterresin, an epoxy resin or an acrylic resin.

Melamine resins which can be used include those which have beendescribed as highly or partially methylated melamine-formaldehyderesins, high amino melamine-formaldehyde resins, mixed ether andbutylated melamine-formaldehyde resins, etc.

The partially methylated melamine-formaldehyde resins generally containa methoxymethyl-methylol functionality such as represented by Formula(VIII): ##STR4##

A series of such partially methylated melamine formaldehyde resins isavailable from American Cyanamid Company under the trade designationsCYMEL 370, 373, 380 and 385 resins.

A series of highly methylated melamine resins containing amethoxy-methyl functionality as represented by Formula (IX): ##STR5##

also is available from Cyanamid under the general trade designationsCymel 300, 301, 303 and 350 resins. The various resins in this seriesdiffer in their degree of alkylation and in monomer content. The monomercontent in Cymel 300 is about 75%; in Cymel 301, about 70%; and Cymel303, about 58%; and in Cymel 350, 68%.

High imino melamine resins contain methoxymethyl-imino functionalitiessuch as may be represented by Formula (X): ##STR6##

A series of melamine-formaldehyde resins known as high imino resins areavailable from Cyanamid under the trade designations Cymel 323, 325 and327.

Mixed ether and butylated melamine resins are available from Cyanamidunder the general trade designations Cymel 1100 resins, and thesecontain an alkoxy methyl functionality as illustrated by Formula (XI):##STR7## wherein R⁷ and R⁸ are independently hydrocarbyl groups, forexample alkyl groups such as methyl, ethyl, butyl or isobutyl groups, orpreferably both R⁷ and R⁸ may be butyl groups.

Cymel 1158 resin is a melamine formaldehyde resin available fromCyanamid which contains butoxy-imino functionality as represented byFormula (XII): ##STR8##

Other useful amino resins available from Cyanamid under the CYMEL®designation include benzoguanamine-formaldehyde resins (CYMEL 1123resin), glycoluril-formaldehyde resins (CYMEL 1170, 1171 and 1172) andcarboxyl-modified amino resins (CYMEL 1141 and 1125).

Suitable polymerizable materials include polyamides. In particular, thepolymerizable materials may be an aliphatic or aromatic polyamide resin.Polyamides are commercially available. Examples of polyamides includethose under the trade designations Zytel available from DuPont, Capronfrom AlliedSignal, Texapol from Hanna, Ashlene from Ashley, Ultramidfrom BASF, Durethan from Bayer, Grilamid from EMS, Vestamid from HulsAmerica, Vydyne from Monsanto, Wellamid from Wellman and others.

Generally speaking, polyamides can be prepared from dicarboxylic acids,diamines, amino acids and lactams. For example, the polyamide resins canbe produced by condensation of equimolar amounts of a saturateddicarboxylic acid with a diamine. Alternatively, the dicarboxylic acidsutilized to form nylons may be aromatic dicarboxylic acids such asisophthalic acid or terephtalic acid. Examples of aliphatic saturateddicarboxylic acids include sebacic, octadecanoic acid, sebacic acid,azelaic acid, undecanedoic acid, glutaric acid, pimelic acid and adipicacid.

Examples of diamines which can be reacted with dicarboxlyic acids toform nylons include diamines such as tetramethylenediamine,pentamethylenediamine, octamethylenediamine, decamethylenediamine,hexadecamethylenediamine and hexamethylenediamine. Examples of aromaticamines which can be utilized include para-phenylenediamine and4,4'-diaminodiphenylsulfone. Polyamides can also be produced by the ringopening of lactams such as polycaprolactam, polybutyrolactam,polypivalolactam, polylauriclactam, poly-11-aminoun-decanoic acid,bis(paraminocyclohexyl)methane dodecanoamide, etc.

Specific examples of polyamides include nylon 6 (polycaprolactam), nylon6/6 (polyhexamethyleneadipamide), nylon 6/10 (condensation product ofhexamethylenediamine and sebacic acid), nylon 6/12, nylon 6/T(polyhexamethylene terephthalamide), nylon 7 (polyenanthamide), nylon 8(polycapryllactam), nylon 9 (polypelargonamide), nylon 10, nylon 11,nylon 12, nylon 55, nylon XD6 (poly metha-xylylene adipamide), nylon6/1, polyβ-alanine, NOMAX® 410 available from DuPont, polyamides underthe trade designations PA 7030 and 5050 available from Dow, and UltramidK 1297/2 available from BASF.

Suitable polymerizable materials include polyimides. Polyimides can beprepared by reacting a diisocyanate with a dianhydride, or a dianhydridewith an aromatic diamine (such as maleic anhydride andmethylenedianiline). Examples of polyimides include KAPTON and VESPELavailable from DuPont.

Suitable polymerizable materials include polyetherimides.Polyetherimides are polymers containing ether and imide linkages. Forexample, polyetherimides can be prepared by reacting at least onediamine, such as m-phenylenediamine or p-phenylenediamine, with at leastone ether dianhydride, such as 2,2-bis(3,4-dicarboxyphenoxy)phenyl!propane dianhydride. Polyetherimides arecommercially available. Examples of polyetherimides include those underthe trade designation ULTEM-1000, ULTEM-4000 and ULTEM-6000 from GeneralElectric, RTP 2101, 2103 and 2105 from RTP and Thermofil W-10FG0100,W-20FG0100 and W-30FG0100 from Thermofil. Polyetherimides also includesilicone polyetherimides.

Suitable polymerizable materials include polyphenylene sulfide resins.Polyphenylene sulfide resins may have the recurring units of Formula(XIII): ##STR9## Polyphenylene sulfide resins can be prepared accordingto U.S. Pat. No. 3,354,129 which is hereby incorporated by reference.Polyphenylene sulfide resins are also commercially available. Examplesof polyphenylene sulfide resins include those under the tradedesignation RYTON® available from Phillips Petroleum and Forton fromHoechst Celanese.

Suitable polymerizable materials include aromatic polysulfones. Aromaticpolysulfones may have the recurring units of Formula (XIV): ##STR10##Aromatic polysulfones are commercially available. Examples of aromaticpolysulfones include those under the trade designation VISTREX PES®available from ICI and UDEL POLYSULFONE® avaialble from Union Carbide.

Suitable polymerizable materials also include polyamideimides.Polyamideimides may be prepared by condensing an imide and an amide.Polyamideimides are commercially available. Examples of polyamideimidesinclude those under the trade designation TORLON™ available from Amocoand Lack E 3560/32 and 3561/27 available from Herberts Gmbh.

Suitable polymerizable materials include polyesterimides. Polyesterimdesare commercially available. Examples of polyesteramides include TERBEC®533 L-33 available from BASF, IMIDEX-E available from General Electricand those made according to U.S. Pat. Nos. 3,426,098 and 3,697,471 whichare herein incorporated by reference.

Suitable polymerizable materials include polyesteramideimides.Polyesteramideimides are commercially available. Examples ofpolyesteramideimides include copolymers of any combination of apolyester, a polyamide and polyimide. Unsaturated polyesters arepreferred as are aromatic polyamides and polyimides.

Suitable polymerizable materials include polyvinyl acetals. Polyvinylacetals are commercially available. Polyvinyl acetals includeethylene-vinyl acetate and copolymers of ethylene-vinyl acetate,especialy copolymers of ethylene-vinyl acetate and polyolefins.

Suitable polymerizable materials include fluorinated polymers.Fluorinated polymers are commercially available. Examples of fluorinatedpolymers include those under the trade designation TEFLON® availablefrom DuPont (polytetrafluoroethylene PTFE), polyperfluoroalkyl vinylether (PFA), polyhexafluoropropylene, fluorinated ethylenepropylenepolymers such as FEP® available from DuPont, and polyvinylidenefluoride.

Suitable polymerizable materials include polycarbonates. Polycarbonatescan be prepared by the phosgenation of such as ethylene glycol,propylene glycol, and bisphenol A. Polycarbonates can alternatively beprepared by the base catalyzed transesterification of thedihydroxyaliphatic and aromatic monomers with a dialkyl or diarylcarbonate, such as diphenyl carbonate. Polycarbonates are commerciallyavailable. Examples of polycarbonates include those under the tradedesignation MAKROLON® available from Bayer, Naxell and Stanuloy from MRCPolymers, Calibre from Dow Plastics and Lexan from GE Plastics.

The polymerizable material may be initially used in combination withmetal oxide sol to make a prepolymer mixture. The polymers according tothe invention are made from a polymerizable material and a metal oxidesol, the prepolymer mixture.

In order to avoid undesirable premature polymerization of any of thepolymerizable materials (resins) used with the inventive compositions, asmall amount of a polymerization inhibitor can be used. Examples of suchinhibitors include hydroquinone, tertiary butyl catechol, methyl etherof hydroquinone, and the like. These inhibitors should be incorporatedin the mixture prior to reaction. An example of a commercially availableinhibitor that can be used is SP-91029, which is a product ofPlasticolors identified as a mixture of 2,6-di-tert-butyl-p-cresol (25%)and vinyl toluene (75%).

The following examples illustrate the preparation of polymerizablematerials with which the metal oxide sols can be combined.

EXAMPLE A

UV-Curable Resin Mixture

A mixture of tris(2-hydroxyethyl)isocyanurate triacrylate (SartomerSR368, 9.0 gm), urethane acrylate (Sartomer CN971 A80, 13.2 gm),bisphenol A ethoxylate (1 EO/phenol) diacrylate (Aldrich Chem., 60 gm),and isobornyl acrylate (Sartomer SR 506, 9.0 gm) in a brown glass bottleis stirred until a homogenous solution is obtained. Subsequently,2-isopropylthioxanthone photoinitiator (0.36 gm) and ethyl4-dimethylaminobenzoate co-photoinitiator (1.08 gm) are added, and theresulting solution is further stirred giving a clear solution.

EXAMPLE B

UV-Curable Resin Mixture

A mixture of tris(2-hydroxyethyl)isocyanurate triacrylate (SartomerSR386, 0.95 gm), urethane acrylate (Sartomer CNN699J25, 1.4 gm), andbenzylmethacrylate (Aldrich Chem., 3.5 gm) is stirred in a brown glassbottle until a homogenous solution is obtained. Subsequently, the resinis mixed with 2-isopropyithioxanthone photoinitiator (0.066 gm) andethyl 4-dimethylaminobenzoate co-photoinitiator (0.19 gm). The resultingmixture is further stirred giving a clear solution.

A "sol", as the term is used herein, refers to a composition comprisinga liquid colloidal dispersion containing a liquid phase and a dispersedphase. The liquid phase of the liquid colloidal dispersion may beaqueous and/or organic, and in particular, may be at least one of waterand organic liquids such as alcohols, glycols and other protic organicsolvents. Organic solvents include methanol, ethanol, propanol,isopropanol, sec-butanol, t-butanol, methoxyethanol,ethoxyethoxyethanol, ethylene glycol and propylene glycol. The liquidphase may also be a liquid or partially liquid substance to which ametal oxide sol can be added such as resin monomers. For example, in thecase where it is desired to incorporate metal oxide sols into a curableresin, the liquid phase of the metal oxide sols may be constituted byone embodiment of a polymerizable material such as curable resinmonomers in liquid form.

The dispersed phase of the liquid colloidal dispersion comprisescondensed partially hydrolyzed chetaled metal oxide precursors. Thecondensed partially hydrolyzed chetaled metal oxide precursors aremicro-clusters which generally have an amorphous shape, although in someembodiments a somewhat symmetrical shape is obtained.

In one embodiment, the condensed partially hydrolyzed chelated metaloxide precursors have an average size (the size is the average diameterof a micro-cluster) of less than about 10 nm, preferably less than about5 nm, and more preferably less than about 2 nm. It will be appreciatedthat some micro-clusters have a size larger than about 10 nm, as theaverage size refers to calculating the average of a random sample ofmicro-cluster diameters, each diameter to be averaged itselfrepresenting the average diameter of a generally amorphous micro-clusterin the random sample. The average size of a micro-cluster can bepreferably determined with a transmission electron microscope, althoughan atomic force microscope can also be useful. If necessary, the sizecan be compared with conventional filler having a known size.

In general, a metal oxide sol can be produced by contacting a metaloxide precursor with a multifunctional compound, typically in a liquidsolvent. The multifunctional compound contains at least one reactablefunctional group and at least one chelating functional group. Thechelating functional group of the multifunctional compound coordinateswith the metal oxide precursor to form a chelated metal oxide precursor.The chelated metal oxide precursor is hydrolyzed by a hydrolyzing agent,for example by contact with water, to provide a metal oxide sol.

Suitable metal oxide precursors are capable of being converted to achelated metal oxide precursor by contact with a compound containing achelating group. Metal oxide precursors include metal organic compoundsand inorganic salts. Metal organic compounds include metal alkoxides andmetal carboxylates. Metal alkoxides and metal carboxylates include metalmethoxides, metal ethoxides, metal isopropoxides, metal propoxides,metal butoxides, metal ethylhexoxides, metal(triethanolaminato)isopropoxides, metal bis(ammonium lacto)dihydroxides,metal bis(ethyl acetoacetato)diisopropoxides, metalbis(2,4-pentanedionate)diisopropoxides, metal acetates, metalethylhexanoates, metal gluconates, metal oxalates, metal propionates,metal pantothenates, metal cyclohexanebutyrates, metaltrifluoroacetylacetonates, metal citrates, and metal methacrylates.Inorganic salts include metal halides and metal nitrates. In a preferredembodiment, the metal oxide precursor is a metal alkoxide.

The metal of the metal oxide precursors include transition metals,alkaline earth metals and metallic elements of Groups 3A, 4A and 5A ofthe periodic table of elements and combinations thereof. Transitionmetals include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc,Ru, Rh, Pd, Ag, Cd, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg and Ac.Alkaline earth metals include Be, Mg, Ca, Sr and Ba. Group 3A metallicelements include B, Al, Ga, In and TI. Group 4A metallic elementsinclude Ge, Sn and Pb. Group 5A metallic elements include As, Sb and Bi.In a preferred embodiment, the metal of the metal oxide precursors is atleast one of aluminum, titanium and zirconium. In another preferredembodiment, the metal of the metal oxide precursors, metal organiccompounds and inorganic salts is not silicon. In embodiments where twoor more metals are present as the metal of the metal oxide precursors,metal organic compounds and inorganic salts, the first metal is one ofthose listed above and the second metal is preferably boron or silicon.

Metal oxide precursors include at least one of transition metalalkoxides, alkali metal alkoxides, alkaline earth metal alkoxides,Groups 3A, 4A and 5A alkoxides, transition metal carboxylates, alkalimetal carboxylates, alkaline earth metal carboxylates, Groups 3A, 4A and5A carboxylates, transition metal halides, alkali metal halides,alkaline earth metal halides, Groups 3A, 4A and 5A halides, transitionmetal nitrates, alkali metal nitrates, alkaline earth metal nitrates andGroups 3A, 4A and 5A nitrates. Preferred metal oxide precursors includemetal organic compounds and inorganic salts of Groups 3A and 4B of theperiodic table of elements such as aluminum alkoxides, aluminum halides,titanium alkoxides, titanium halides, zirconium alkoxides and zirconiumhalides.

Specific examples of metal oxide precursors include aluminumtriethoxide, aluminum isopropoxide, aluminum sec-butoxide, aluminumtri-t-butoxide, aluminum lactate, aluminum nitrate, aluminum chloride,aluminum bromide, aluminum fluoride, aluminum iodide, calcium acetate,calcium ethylhexanoate, calcium gluconate, calcium oxalate, calciumpropionate, calcium pantothenate, calcium cyclohexanebutyrate, calciumnitrate, calcium chloride, calcium bromide, calcium fluoride, calciumiodide, magnesium acetate, magnesium trifluoroacetylacetonate, magnesiummethoxide, magnesium ethoxide, magnesium methylcarbonate, magnesiumgluconate, magnesium nitrate, magnesium chloride, magnesium bromide,magnesium fluoride, magnesium iodide, tin acetate, tin oxalate, tinchloride, tin bromide, tin fluoride, tin iodide, tinbis(acetylacetonate)dibromide, tin bis(acetylacetonate) dichloride,titanium methoxide, titanium ethoxide, titanium isopropoxide, titaniumpropoxide, titanium butoxide, titanium ethylhexoxide, titanium(triethanolaminato)isopropoxide, titanium bis(ammoniumlacto)dihydroxide, titanium bis(ethyl acetoacetato)diisopropoxide,titanium bis(2,4-pentanedionate)diisopropoxide, titanium chloride,titanium bromide, titanium fluoride, titanium iodide, zinc acetate, zincmethacrylate, zinc stearate, zinc cyclohexanebutyrate, zinc nitrate,zinc chloride, zinc bromide, zinc fluoride, zinc iodide, zirconiumethoxide, zirconium isopropoxide, zirconium propoxide, zirconiumsec-butoxide, zirconium t-butoxide, zirconium acetate, zirconiumcitrate, zirconium chloride, zirconium bromide, zirconium fluoride,zirconium iodide, and combinations of two or more of the abovecompounds.

The following example illustrates the preparation of a metal oxideprecursor.

EXAMPLE C

Preparation of Metal Oxide Precursor

A mixture of aluminum triisopropoxide (20.4 gm) and 2-methoxyethanol (76gm) in a round bottle flask is heated to 90° C. for one hour to obtain ahomogenous solution. Subsequently, part of the solvent (mainlyisopropanol) is removed under vacuum to give a clear, low viscositysolution (54.5 gm), containing 46% aluminum trimethoxyethoxide.

The multifunctional compound is any compound capable of coordinating toa metal oxide precursor through a chelating functional group. Themultifunctional compound which is contacted with the metal oxideprecursors contains at least one reactable functional group and at leastone chelating functional group. The chelating functional groupsgenerally coordinate through nitrogen, oxygen, sulfur, phosphorus,arsenic and/or selenium atoms; thus chelating functional groups containat least one of N, O, S, P, As and Se atoms. Chelating functional groupsinclude polyphosphates, β-diketones, acetal acetates, aminocarboxylicacids, hydroxycarboxylic acids, hydroxyquinolines, polyamines,aminoalcohols, aromatic heterocylic bases, phenols, aminophenols,oximes, phosphonic acids, Schiff bases, tetrapyrroles, thiols,xanthates, and salicylic acid. The chelating functional groupscoordinate to (react with) the metal of the metal oxide precursor insuch a way to form a coordinated or chelated metal oxide complex thatcan prevent gelation of the sol by retarding, preventing or partiallypreventing hydrolysis and/or condensation.

The reactable functional group of the multifunctional compound does notsubstantially interact or bond with the metal oxide precursor. Instead,the reactable functional group interacts with a polymerizable materialwith which the metal oxide sols are subsequently combined. In otherwords, the reactable functional group is capable of reacting,interacting or bonding with a polymerizable material, a polymer orpolymer substituent. The reactable functional group may be incorporatedinto the polymer backbone during polymerization, may be incorporatedinto the polymer during crosslinking, and/or may be incorporated intothe polymer by reacting with a side chain, substituent group or afunctional group on the polymer. For example, reactable functionalgroups include curable functional groups, photoreactive functionalgroups, thermocurable groups, interactable groups, solvateable groupsand condensable groups. Reactable functional groups include an acrylicunsaturated bond and other radiation curable aliphatically unsaturatedfunctional groups, such as vinyl and acrylamide groups, styryl, acrylic,hydroxy, amine, carboxylic, thio, and phenol groups. Reactablefunctional groups can ensure good compatibility of the metal oxide solwith the polymerizable material with which the metal oxide sols aresubsequently combined. The resulting combination of the metal oxide soland the polymerizable material provides a polymer nanocomposite in whichthe partially hydrolyzed chelated metal oxide precursor is uniformlydistributed in the resultant polymer at a molecular level.

In a few embodiments, especially when a relatively small amount orequivalents of the multifunctional compound (compared to the metal oxideprecursor) is used, the reactable functional group may initially chelatewith the metal oxide precursor; but once the partially hydrolyzedchelated metal oxide precursor or the micro-clusters are combined withthe polymerizable material, the reactable functional group uncoordinateswith the metal oxide precursor and reacts, interacts or bonds with thepolymerizable material.

Multifunctional compounds are commercially available and/or can beprepared by reacting a compound containing a chelating functional groupwith a compound containing a reactive functional group. For example, amultifunctional compound can be prepared by reacting a compoundcontaining a chelating functional group such as 4-aminosalicylic acidwith a compound containing a reactive functional group such asmethacryloylchloride to provide 4-methacryloylamino salicylic acid. In apreferred embodiment, the multifunctional compound is prepared byreacting a compound containing a chelating functional with a compoundcontaining a reactive functional group such as a vinyl, an acrylic groupor a hydroxyl group.

Specific multifunctional compounds which can be used in accordance withthe invention include acrylic acid/maleic acid copolymer, alkoxylateddiamines, alkyl-diaminepolyacetic acids, aminoalkylphosphonic acid,amino tris(methylene phosphonic acid), anthranilic acid, benzotriazole,citric acid, diethylenetriamine pentaacetic acid, diethylenetriaminepenta(methylene phosphonic acid), ethylenediaminetetraacetic acid,gluconic acid, glucoheptonoic acid, hexamethylenediamine tetra(methylenephosphonic acid), lignosulfonic acids, 2-(methacryloyloxy)ethylacetoacetate, 5-(methacryloyloxy)methyl salicylic acid,4-methacryloylamino salicylic acid, hydroxyethyl salicylate,hydroxyethyl salicylamide, methylvinyl ether/maleic acid copolymer,o-hydroxybenzoylacetone, 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one,3-hydroxy-2-methyl-4-pyrone, 8-hydroxyquinolone,N-hydroxyethylenediamine triacetic acid, hydroxy-ethylidene diphosphonicacid, hydroxyethane diphosphonic acid, nitrilotriacetic acid, sorbitol,tolyltrizole, o-hydroxybenzoylacetone, 2-hydroxydibenzoylmethane andN-(acetoacetyl)glycine.

Supplemental multifunctional compounds, which contain at least one of areactable functional group and a chelating functional group, canoptionally be used in addition to the multifunctional compound.Supplemental multifunctional compounds include polyacrylic acid,poly(ethylene glycol) methacrylate, and poly(propylene glycol)methacrylate. Supplemental multifunctional compounds are contacted withthe metal oxide precursor just before, at the same time, or just afterthe multifunctional compound and the metal oxide precursor are combined.

The following example illustrates the preparation of a usefulmultifunctional compound.

EXAMPLE D

Preparation of a Multifunctional Compound

To a solution of purified toluene/diethyl ether (30 ml/30 ml),4-aminosalicylic acid (6.58 gm, 43 mmole) is added in a glass vessel.After cooling to below 5° C. (in an ice/water bath),methacryloylchloride (5 gm, 43 mmole) is slowly added to the mixturewhile stirring. The resulting mixture is stirred for three hours, duringwhich the temperature is allowed to increase gradually to roomtemperature. The solid fraction is collected by filtration and thenwashed several times with toluene/diethyl ether. The organic extractsare combined, washed with a small amount of water, and dried with Na₂SO₄. Removal of the solvent under vacuum gives a colorless solid (4.5gm). FTIR of the solid confirms the formation of4-(methacryloylamino)salicylic acid.

The metal oxide sol can be prepared in accordance with the followingprocedure. A metal oxide precursor is contacted with a multifunctionalcompound. In a preferred embodiment, the metal oxide precursor isprovided in an appropriate amount of solvent, preferably in an organicsolvent such as an alcohol or glycol solvent. In another preferredembodiment, the organic solvent optionally contains a small amount ofwater, for instance, about 0.01% to about 5% by weight of the organicsolvent, and preferably about 0.1% to about 2% by weight of the organicsolvent. In this embodiment, the metal oxide precursor is preferably ametal halide.

In another embodiment, the metal oxide precursor is provided in thepolymerizable material in which the subsequently formed metal oxide solswill be incorporated. For example, if the metal oxide sols are to beincorporated into a curable resin system, the metal oxide precursor canbe provided in the monomers of the uncured resin. The molar ratio of theamount of the metal oxide precursor combined with the multifunctionalcompound is from about 1:0.1 to about 1:3, preferably from about 1:0.2to about 1:1.5, and more preferably from about 1:0.3 to about 1:1.2(assuming the multifunctional compound contains a bidentate chelatingfunctional group).

In one embodiment, when contacting the metal oxide precursor with amultifunctional compound, it is desirable for the multifunctionalcompound to coordinate with at least about 10% of the chelateable siteson the metal oxide precursor molecules (considering the number ofchelateable sites on all of the metal oxide precursor molecules in agiven reaction vessel). In another embodiment, it is desirable for themultifunctional compound to coordinate with at least about 25% of thechelateable sites. In yet another embodiment, it is desirable for themultifunctional compound to coordinate with at least about 50% of thechelateable sites. In still yet another embodiment, it is desirable forthe multifunctional compound to coordinate with at least about 75% ofthe chelateable sites. The extent to which the multifunctional compoundcoordinates with the metal oxide precursor depends upon the relativeamounts of the materials used, the number of chelateable sites on themetal oxide precursor molecules, and whether the multifunctionalcompound contains a bidentate, tridentate, etc., chelating functionalgroup. NMR can be used to monitor the coordination of the metal oxideprecursor.

The metal oxide precursor is contacted with a multifunctional compoundat a temperature suitable to permit the multifunctional compound tocoordinate with the metal oxide precursor. In one embodiment, thetemperature is from about 0° C. to about 50° C., but preferably aboutroom temperature. It is important to ensure that the chelatingfunctional group of the multifunctional compound coordinates with themetal oxide precursor prior to partial hydrolyzation with a hydrolyzingagent such as water.

Subsequent to treatment with the chelating compound, the chelated metaloxide precursor is partially hydrolyzed by contact with a hydrolyzingagent. That is, unchelated atoms, groups or sites which are directly orindirectly connected to the metal atom of the chelated metal oxideprecursor are hydrolyzed thereby providing a monomer of a partiallyhydrolyzed chelated metal oxide precursor. The chelated atoms or groupsare generally not hydrolyzed, although a small fraction of the chelatedgroups may be hydrolyzed in some instances. So long as the percentage ofchelated sites remains as described above, problems are not generallyencountered. In one embodiment, the temperature at which the chelatedmetal oxide precursor is partially hydrolyzed is from about 0° C. toabout 50° C., but preferably about room temperature.

Partial hydrolysis may be carried out by contacting the chelated metaloxide precursor with a hydrolyzing agent such as water, and preferablydeionized water. The hydrolyzing agent converts the unchelated atoms orgroups to hydroxyl groups. In one embodiment, the molar ratio of thechelated metal oxide precursor to water is about 1:0.5 to about 1:3, andpreferably about 1:1 to about 1:2. In one embodiment, the chelated metaloxide precursor is contacted with a hydrolyzing agent in a solvent andpreferably an organic solvent. In another embodiment, the chelated metaloxide precursor is contacted with a hydrolyzing agent in resin monomersand/or other ingredients. In this connection, the metal oxide sols canalso be prepared in resin monomers without a solvent, or in the absenceof a non-reactive element, such as a non-reactive diluent, as set forthin Example E below.

The partially hydrolyzed chelated metal oxide precursors are reactivemonomers. Once formed, the monomers of the partially hydrolyzed chelatedmetal oxide precursor proceed to form the metal oxide sol of theinvention by limited polycondensation. Since the monomers are partiallychelated, the polycondensation is controlled whereby micro-clusters ofseveral monomers are formed. That is, since polycondensation iscontrolled, the micro-clusters do not agglomerate and/or aggregate intogel form. Polycondensation may be controlled by varying the amount ofhydrolyzing agent used and varying the percentage of chelated sites onthe metal oxide precursor molecules.

On average, the oligomers constitute micro-clusters which may be made upof about 2 to about 5,000 partially hydrolyzed chelated metal oxideprecursor monomers. In a preferred embodiment, the micro-clusters may bemade up of about 3 to about 1,000 partially hydrolyzed chelated metaloxide precursor monomers. In a more preferred embodiment, themicro-clusters may be made up of about 4 to about 100 partiallyhydrolyzed chelated metal oxide precursor monomers. In an even morepreferred embodiment, the micro-clusters may be made up of about 5 toabout 25 partially hydrolyzed chelated metal oxide precursor monomers.The average number of monomers which constitute a given micro-clustercan be determined by considering at least one of a number of parametersincluding the average size of a micro-cluster, the identity of the atomsof the partially hydrolyzed chelated metal oxide precursor, the relativeamounts of the micro-clusters of the partially hydrolyzed chelated metaloxide precursor and the liquid solvent (density), the length of time ofthe polycondensation reaction, the nature of the metal oxide precursorand the multifunctional compound, the extent (percentage) ofcoordination and the amount of hydrolyzing agent used.

The micro-clusters of the metal oxide sol may have an amorphous shape ora symmetrical shape. In this connection, the polycondensation reactionis a random polymerization. Thus, the micro-clusters may assume one ormore of linear configuration, branched configuration, clusterconfiguration, dendrimer configuration, and cyclic configuration.

The resultant metal oxide sols are stable. Once made, the metal oxidesols can be stored as a colloidal dispersion for extended periods oftime. It is believed that this is because the micro-clusters tend not toagglomerate. For example, in one embodiment, the metal oxide sols can bestored (colloidal dispersion maintained) for up to about 10 weeks, andin another embodiment, up to about 25 weeks at room temperature in asealed container.

The following examples illustrate the preparation of useful metal oxidesols.

EXAMPLE E

Preparation of Metal Oxide Sol

A mixture of aluminum triisopropoxide (2.99 gm, 14.7 mmole) and2-methoxyethanol (13 gm) is stirred at 90° C. until a clear solution isobtained.

After cooling to room temperature, 2-(methacryloyloxy)ethyl acetoacetatechelating agent (1.6 gm, 7.5 mmole) is first added to the solution andthe resulting solution is stirred for 30 minutes before the addition ofdeionized water (0.26 gm, 14.7 mmole). The resulting mixture is furtherstirred for one hour to obtain a clear and stable metal oxide sol basedon aluminum which shows no gel formation even after storage for threemonths.

Without using the multifunctional compound, the aluminum alkoxidesolution quickly generates gelatinous white precipitate upon exposure tomoisture.

EXAMPLE F

Preparation of Metal Oxide Sol

A mixture of aluminum triisobutoxide (1.56 gm, 6.3 mmole) and 2-propanol(3.8 gm) is stirred for ten minutes at room temperature. To thesolution, 2-(methacryloyloxy)ethyl acetoacetate chelating agent (0.65gm, 3 mmole) is added and the resulting solution is stirred for thirtyminutes. The addition of deionized water (0.11 gm, 6.3 mmole), followedby stirring for one hour, gives a clear and stable metal oxide sol basedon aluminum which shows no gel formation even after storage for threemonths.

Without the multifunctional compound, the aluminum alkoxide solutionquickly generates gelatinous white precipitate upon exposure tomoisture.

EXAMPLE G

Preparation of Metal Oxide Sol

To a solution of aluminum trisobutoxide (0.24 gm, 0.98 mmole) and2-methoxyethanol (0.76 gm), 4-(methacryloylamino)sallcylic acid (0.19gm, 0.92 mmole) is added and the solution is stirred for thirty minutes.The addition of deionized water (17 mg, 0.94 mmole) and stirring for onehour gives a clear and stable metal oxide sol based on aluminum.

EXAMPLE H

Preparation of Metal Oxide Sol

Hydroxyethyl salicylate (1.87 gm, 10 mmol) is added to a solution ofaluminum tributoxide (4.12 gm, 17 mmol) and methoxyethanol (11.5 gm) andstirred for 30 minutes. To the solution, deionized water (0.47 gm, 26mmol) is added and the resulting solution is stirred overnight to give aclear, stable metal oxide sol.

EXAMPLE I

Preparation of Metal Oxide Sol

Hydroxyethyl salicylamide (1.24 gm, 6.9 mmol) is added to a solution ofaluminum tributoxide (4.123 gm, 17 mmol) and methoxyethanol (16 gm) andstirred for 30 minutes. To the solution, deionized water (0.47 gm, 26mmol) is added and the resulting solution is stirred overnight to give aclear, stable metal oxide sol.

EXAMPLE J

Preparation of Metal Oxide Sol

Hydroxyethyl salicylate (0.753 gm, 4.1 mmol) is added to a solution ofzirconium tetrapropoxide (3.353 gm, 10.2 mmol) and methoxyethanol (36gm) and stirred for 30 minutes. To the solution, deionized water (0.37gm, 20.4 mmol) in 2-methoxyethanol (2 gm) is added and the resultingsolution is stirred overnight to obtain a clear, stable metal oxide sol.

EXAMPLE K

Preparation of Metal Oxide Sol

To a solution of titanium tetrapropoxide (49.72 gm, 0.175 mole) andmethoxyethanol, methoxyethanol (28.4 gm) in a glass vessel,3-hydroxy-2-methyl-4-pyrone (14.5 gm, 0.115 mole) is added and theresulting solution is stirred overnight to obtain a clear, stable metaloxide sol.

EXAMPLE L

Preparation of Metal Oxide Sol

3-Hydroxy-2-methyl-4-pyrone (5.49 gm, 0.079 mol) is added to a solutionof aluminum tributoxide (21.46 gm, 0.147 mol) in a 2-methoxyethanol (45gm) and stirred for 30 minutes. To the solution, deionized water (2.96gm, 0.164 mol) in methoxyethanol is added and the resulting solution isstirred overnight to obtain a clear, stable metal oxide sol. The sol isstable and no gelation is observed even after storage for six months atroom temperature.

EXAMPLE M

Preparation of Metal Oxide Sol

A mixture of N(acetocetyl)glycine (3.18 gm, 20 mmol) and butyl glycidylether (2.6 gm, 20 mmol) in methoxyethanol (1.5 gm) is stirred at 80° C.for 5 hrs to form a corresponding glycine ester having a hydroxy group.The above mixture (1.32 gm) is then added to a solution containingaluminum tributoxide (2.57 gm, 10.4 mmol) and methoxyethanol (10 gm) andthe resulting solution is stirred for 30 minutes. To the mixture, asolution of deionized water (0.37 gm, 20.4 mmol)/methoxyethanol (0.3 gm)is added and the resulting mixture is stirred overnight to generate ametal oxide sol based on aluminum.

EXAMPLE N

Preparation of Metal Oxide Sol

A homogeneous mixture of aluminum tributoxide (0.37 gm, 1.5 mmol) andbisphenol A ethoxylate (2EO/PhOH) (0.3 gm) is prepared in a vial.Subsequently, 3-Hydroxy-2-methyl-4-pyrone (0.066 gm, 0.53 mmol) is addedand the resulting mixture is stirred for 30 minutes. After addition ofdeionized water (0.04 gm, 2.3 mmol), the resulting mixture is stirredovernight and then heated to 80° C. under vacuum giving a metal oxidesol as a viscous clear liquid.

EXAMPLE O

Preparation of Metal Oxide Sol

o-Hydroxybenzoylacetone (0.62 gm, 3.5 mmol) is added to a solution ofzirconium tetrabutoxide (3.84 gm, 10 mmol) in methoxyethanol (5 gm) andthe solution is stirred for 30 minutes. To the solution, deionized water(0.036 gm, 20 mmol) in methoxyethanol (1 gm) is added while stirring andthe resulting solution is stirred overnight to give a clear sol. To thesol, bisphenol A bis diethylene glycol (4.2 gm) is added and the mixtureis slowly heated to 80 ° C. under vacuum to remove volatile components.The resulting metal oxide sol based on zirconium is yellow; but clearviscous liquid (6.0 gm).

EXAMPLE P

Preparation of Metal Oxide Sol

A solution containing aluminum tributoxide (2.46 gm, 10 mmol) andtetraethyl orthosilicate (2.08 gm, 10 mmol) is prepared inmethoxyethanol (50 gm). To the solution, 3-Hydroxy-2-methyl-4-pyrone(0.5 gm, 4 mmol) is added and the resulting solution is stirred for 30minutes. To the solution, water (0.63 gm, 35 mmol) in methoxyethanol(1.5 gm) is added and the solution is stirred overnight to generate aclear stable metal oxide sol based on aluminum and silicon.

The metal oxide sol, and particularly the micro-clusters, may becombined with a polymerizable material up to about 70% by weight of thetotal composition. In one preferable embodiment, at least about 0.1% byweight of the total composition is the metal oxide sol, and morepreferably from about 0.5% to about 40% by weight of the totalcomposition is a metal oxide sol. The amount of metal oxide sol usedwith a particular polymerizable material is determined by processabilityand performance of the prepolymer mixture and the resultant polymer madewith the metal oxide sol by viscosity requirements, by mechanical,electrical and thermal properties, and by other concerns. The maximumamount used may be determined, however, in a practical respect by thedesired mechanical parameters of the resultant polymer. In oneembodiemnt, the amount of polymerizable material which may be combinedwith a metal oxide sol to make a prepolymer mixture is from about 30% toabout 99.9% by weight. In another embodiemnt, the amount ofpolymerizable material which may be combined with a metal oxide sol tomake a prepolymer mixture is from about 60% to about 99.5% by weight.

Other ingredients which may be dispersed into the inventive compositionsprior to or after polymerization and/or curing include one or more ofthe following: fillers, fibrous reinforcing materials, pigments, moldrelease agents, thermoplastic and elastomeric polymeric materials,shrink control agents, wetting agents, antifoam agents and thickeners.

In most embodiments, the metal oxide sol is simply combined with apolymerizable material, and optionally various other ingredients, toform a prepolymer mixture, the prepolymer mixture is then polymerized,cured heated or cooled to form the polymers of the present invention. Inembodiments involving a thermosetting resin, the metal oxide sol iscombined with the thermosetting resin prior to curing. The prepolymermixture of the thermosetting resin and the metal oxide sol is preferablymixed followed by curing (polymerization and/or crosslinking). In someembodiments, the thermosetting resin can be B-staged (partially cured)before it is combined with the metal oxide sol to form a prepolymermixture. Curing is accomplished in any manner consistent with theparticular characteristics of the thermosetting resin. For example,curing may be initiated light such as UV light or visible light, achange in temperature such as heating or cooling, exposure to a curinginitiator such as oxygen, or any other means known to those skilled inthe art.

In any of these embodiments, the liquid phase of the metal oxide sol canbe removed from a prepolymer mixture prior to curing. In anotherembodiment, the liquid phase of the metal oxide sol can be removedbefore mixing the sol with the polymerizable material. In yet anotherembodiment, the liquid phase of the metal oxide sol may be removedsubsequent to curing, polymerization or heating the prepolymer mixture.

In embodiments where the polymerizable material is a thermoplasticresin, the metal oxide sol is combined with the thermoplastic resinprior to polymerization or after polymerization of the resin but whenthe thermoplastic resin is in condition to be combined with the metaloxide sol to form a prepolymer mixture. For example, in embodimentswhere a thermoplastic resin is polymerized, the metal oxide sol iscombined with the resin after the thermoplastic resin is heated so thatit is in the molten state or the liquid state. In this embodiment, thepolymer according to the present invention is made by simply cooling theprepolymer mixture of the molten or liquid thermoplastic resin and themetal oxide sol. In another embodiment, the metal oxide sol is combinedwith the thermoplastic resin (prior to polymerization) to form aprepolymer mixture and then the prepolymer mixture is polymerized toform the polymer of the present invention. In any of these embodiments,the liquid phase of the metal oxide sol may be removed prior topolymerization, heating and/or cooling (such as by evaporation), priorto combining the metal oxide sol and thermoplastic resin, or afterpolymerization, heating and/or cooling.

The micro-clusters of the metal oxide sols mix homogeneously with thepolymerizable material in which they are incorporated. Such a clearcomposition can be transparent to a photocure source regardless ofthickness, and not susceptible to metal oxide precipitation as areconventional photocurable resins containing metal oxide fillers.

When the metal oxide sol is combined with a polymerizable material, highshear mixing is not required to produce a homogeneous composition. Insome embodiments where the metal oxide sol is added to a polymerizablematerial, a transparent composition is obtainable. The fact that themetal oxide sol is used in the sol form has an added benefit in that itis not necessary to use organic solvents.

The prepolymer mixtures containing the polymerizable materials and themicro-clusters (made with metal oxide sols) may be processed usingconventional techniques associated with processing the polymerizablematerial. For example, when the prepolymer mixture is a particularcurable resin system containing the micro-clusters, the prepolymermixture is cured and processed in a conventional manner associated withthe particular curable resin system.

It is speculated that the micro-clusters of the metal oxide sols bond orinteract with the polymerizable material via the reactable functionalgroup of the multifunctional compound used to make the polycondensedpartially hydrolyzed chelated metal oxide precursor duringpolymerization, curing, heating and/or cooling (or participate in thepolymerization of the polymerizable material) thereby becoming a part ofand dispersed within the resultant polymer on the molecular level.Again, while not wishing to be bound by any specific mechanism ortheory, in particular, it is believed that the polycondensed partiallyhydrolyzed chelated metal oxide precursor may be incorporated into thepolymer backbone, attached as a pendent group to the polymer,incorporated as a crosslinking group, or somehow bonded uniformly to theresultant polymer.

In some embodiments, polymerization, curing, heating and/or cooling neednot occur immediately after the metal oxide sol is combined with thepolymerizable material to form the prepolymer mixture. The prepolymermixture of the metal oxide sol and the polymerizable material may bestored until it is needed or ready for use. In embodiments where thepolymer according to the present invention is used as a coating, storagecapabilities are desirable.

The polymers according to the present invention may have one or more ofnumerous desirable properties. Desirable properties include abrasionresistence, adhesion enhancement, chemical attack resistance, coronaresistance (for example, due to high field intensities), high metalcontent, homogeneity, mechanical strength, oxide erosion resistance,plasma etch resistance, prevention of void formation, and resistance tomonoatomic oxygen attack.

While not wishing to be bound by any specific mechanism or theory, it isspeculated that the polymer made with the metal oxide sols describedherein may be substantially void free. By "void free" it is meant thatthe polymer is pinhole-free, lacking holes or other fissures on thesurface or in the volume thereof. In one embodiment, substantially voidfree indicates that a polymer containing the micro-clusters is more thanabout 99% pinhole-free. In another embodiment, substantially void freeindicates that a polymer containing the micro-clusters is more thanabout 99.5% pinhole-free. In yet another embodiment, substantially voidfree indicates that a polymer containing the micro-clusters is more thanabout 99.9% pinhole-free.

The polymers containing the micro-clusters may also be characterized bytheir homogenous nature. Given the size of the micro-clusters and thetendency not to agglomerate, a homogenous mixture with a polymerizablematerial is easy to achieve. The term "transparent" as used herein withrelation to the resulting polymer refers to the homogeneity of thepolymer at the molecular level. In some embodiments, the polymer isideally suitable for photocure processing due to its potentialtransparency.

Another advantage associated with using polymers made with metal oxidesols is the capability to make a very thin polymer substrate or coating.This is due to the lack of particulate matter in the resulting polymer.Alternatively, thick polymer substrates or coatings are easily achieveddue to the transparent nature of the initial prepolymer mixture whichgreatly enhances the ease of curing and/or polymerizing thepolymerizable material. Yet another advantage associated with usingpolymers made with metal oxide sols is the capability to maximize theamount of metal in a polymer.

The polymers made with metal oxide sols have resistance to attack fromplasma such as oxygen plasma. The polymers made with metal oxide solsare stable in a plasma environment, which is a very severe andpotentially damaging environment. Accordingly, the present inventionalso relates to methods of increasing the oxygen plasma resistance ofpolymers by using the metal oxide sols described herein. As a result,the polymers made with metal oxide sols are useful in electricaldevices, such as microelectronic materials, especially those involvedwith plasma etching, cleaning, de-scumming, stripping and passivating ofmicroelectronic materials.

The polymer made with metal oxide sols has excellent electrical andthermal insulation characteristics. In particular, the polymer accordingto the invention is corona resistant. Accordingly, the present inventionalso relates to methods of increasing the corona resistance of polymersby using the metal oxide sols described herein. The polymer also hasdesirable mechanical characteristics. As a result, the polymer isdesirable for use in coating components of electrical devices. Thesedevices encounter considerable electrical stress and their performanceand life are substantially enhanced by the use of a corona resistantpolymer coating.

In one embodiment, the prepolymer mixture containing a thermosettingresin, metal oxide sol and a photosenstizer is applied to a substrate byany of a number of known coating techniques, which include but are notlimited to spin coating, dip coating, spray coating, electricalcomponents coating, die coating, and bar coating. The viscosity of theprepolymer mixture need only be in the coatable range to afford the useof this wide array of coating techniques.

The coated substrate is then exposed in a conventional manner to aphotocuring source. Whether the photocure is by UV or visible lightdepends on the photosensitizer used in the prepolymer mixture. Becausethe prepolymer mixture is transparent and readily transmits theirradiated light from the photocure source, the mixture easily achievesa complete, uniform cure. The thickness of the polymer coating is oflittle or no importance, other than as a matter of practical efficiencydue to cost and end use, such as potential packing density which may beenhanced by the use of very thin coatings. The cured polymer coating issubstantially transparent, as is the prepolymer mixture prior to thecuring process.

Appreciable amounts of precipitates are not formed if the prepolymermixture is stored. In other words, noticeable agglomeration of themicro-clusters does not generally occur. In one embodiment, theprepolymer mixture can be stored (colloidal dispersion maintained) forup to about 10 weeks, and in another embodiment, up to about 25 weeks atroom temperature in a sealed container. Storage is preferably effectedin a dry, dark, room temperature environment.

The following examples illustrate the process, prepolymer mixtures andpolymers of the present invention. Unless otherwise indicated in thefollowing examples and elsewhere in the specification and claims, allparts and percentages are by weight, all temperatures are in degreesCentigrade, and pressure is at or near atmospheric pressure.

Example 1

Polymer Made With Metal Oxide Sol

The metal oxide sol from Example E (17 gm) is charged into a flask andthe volatiles are removed under vacuum to give a clear viscous residue(2.9 gm). To the residue, the Resin Mixture from Example A (5.62 gm),isobornyl acrylate (1.25 gm) and 2-methoxyethanol (2 gm) are added, andthe resulting mixture is stirred to obtain a clear solution. The clearsolution is applied onto a glass plate and UV-cured for one minute underN₂ using a BLAK-RAY UV Lamp B™ (UVP Corp., Upland, Calif.) forming aclear hard film having good adhesion to the substrate.

Example 2

Polymer Made With Metal Oxide Sol

A solution containing the aluminum trimethoxyethoxide solution fromExample C (1 gm), isobornyl acrylate (3 gm), trimethylolpropanetriacrylate (0.36 gm), 2-(methacryloyloxy)ethyl acetoacetate (0.34 gm),2-isopropylthioxanthone photoinitiator (0.05 gm), and ethyl4-dimethylaminobenzoate co-photoinitiator (0.14 gm) is stirred at roomtemperature for thirty minutes. After the addition of deionized water(0.03 gm), the resulting solution is further stirred for one hour.Removal of the volatiles under vacuum gives a clear solution (4.1 gm).The solution is bar-coated onto a glass plate and UV-cured for oneminute under N₂ giving a clear, hard film with good adhesion to thesubstrate.

The identical solution without the 2-(methacryloyloxy)ethyl acetoacetatemultifunctional compound is also prepared. In this case, however, thesolution becomes opaque upon addition of water, and gradually generatesa white precipitate. Attempts to form a clear uniform coating areunsuccessful due to the formation of gelatinous white precipitatesduring the application of the coating.

Example 3

Polymer Made With Metal Oxide Sol

To a homogenous solution containing isobornyl acrylate (3 gm),trimethylolpropane triacrylate (0.5 gm), and aluminum triisobutoxide(0.67 gm), 2-(methacryloyloxy)ethyl acetoacetate (0.54 gm) is added, andthe resulting solution is stirred for thirty minutes at roomtemperature. After the addition of 2-isopropylthioxanthonephotoinitiator (0.05 gm), ethyl 4-dimethylaminobenzoateco-photoinitiator (0.14 gm), and deionized water (0.05 gm), theresulting mixture is stirred at room temperature for one hour giving aclear solution. The clear solution is then applied to a glass plate andUV-cured for one minute under N₂ giving a clear and hard film, with goodadhesion to the substrate.

Example 4

Polymers Made With Metal Oxide Sols

Three compositions Examples 4-1, 4-2 and 4-3, containing a metal oxidesol based on aluminum, shown in Table I, are prepared by:

(1) mixing the Resin Mixture prepared in Example A and the aluminumtrimethoxyethoxide (ATME) solution prepared in Example C;

(2) adding 2-(methoacryloyloxy)ethyl acetoacetate (MEAA);

(3) stirring for thirty minutes;

(4) adding deionized water; and

(5) stirring for one hour.

The resulting solutions are clear and low in viscosity, and coatable byvarious techniques, including spin and spray coatings. No change inviscosity and clarity is observed, even after aging over three months atroom temperature, in the dark. The compositions are cast onto glassplates and UV-cured for one minute under N₂ giving clear, hard filmshaving good adhesion to the substrate.

                  TABLE I    ______________________________________    POLYMERS CONTAINING METAL OXIDE SOL          AMOUNT OF    EXAM- RESIN FROM ATME SOLUTION    PLE   EXAMPLE A  FROM EXAMPLE C MEAA  WATER    ______________________________________    4-1   3.9 gm     1.1 gm         0.27 gm                                          0.04 gm    4-2   3.4 gm     2.67 gm        0.55 gm                                          0.09 gm    4-3   2.0 gm     3.3 gm         0.40 gm                                          0.11 gm    ______________________________________

Corona Resistance Testing

The compositions from Examples A, 4-1 and 4-2 are bar-coated at variouslevels on the polyimide surface of 3"×31" polyimide (76.2 μm)/adhesive(20.3 μm)/copper (107μm) laminates (GTS FLEXIBLE MATERIALS, INC.,Warwick R.I.). The coated substrates are subsequently heated to 60°-80°C. and exposed to a BLAK-RAY UV Lamp Model B™ (UVP Corp., Upland,Calif.) for one minute under N₂. Test samples are also prepared bycoating on a 3"×3" Cu plate having a thickness of 0.83 mm as describedabove. The cured films exhibited good adhesion to these substrates andno delamination is observed. The cured films are tested for coronaresistance by a needle point corona resistance test which follows amodified ASTM D2275-80 test method. The electrode assembly for the testconsists of a needle point electrode and plane arrangement with a 1 mmair gap between the electrode and the sample. The plane electrodecomprises the test substrate/sample whether coated, uncoated, etc.

The test results set forth in Table II demonstrate the enhancedperformance of the subject coating over the use of a conventionalcoating (Example A) or no coating, with respect to product life, i.e.,time to coating failure due to corona attack.

                  TABLE II    ______________________________________    RESULTS OF NEEDLE POINT CORONA RESISTANCE TESTING            Sample            Description            (ATME +            Coating Applied                                             Time to    Composition            MEAA)/             Thickness                                       Voltage                                             Failure    Example Resin     Substrate                               (microns)                                       (kV)  (hours)    ______________________________________    no coating        polyimide/                               0       5.2   11.6                      copper    no coating        polyimide/                               0       5.2   14.2                      copper    A       0         polyimide/                               15      5.2   30.8                      copper    A       0         polyimide/                               18      5.2   41.2                      copper    4-1     0.2       polyimide/                               10      5.2   74.9                      copper    4-1     0.2       polyimide/                               9       5.2   99.8                      copper    4-2     0.52      polyimide/                               12      5.2   134.4                      copper    4-2     0.52      polyimide/                               12      5.2   117.2                      copper    4-2     0.52      polyimide/                               12      5.2   96.8                      copper    A       0         copper   99      5.2   25    A       0         copper   99      5.2   16.6    4-1     0.2       copper   99      5.2   315.4    ______________________________________

Comparative Example 1

Polymer Without Multifunctional Compound

A composition identical to that of Example 4-2, but without themultifunctional compound is also prepared. In this case, however; thesolution becomes opaque upon addition of water and gradual precipitationof aluminum oxide gel is observed. The same composition containingneither mutlifunctional compound nor water is also prepared. Thesolution, when applied onto a glass plate, quickly generates a whiteprecipitate, resulting in the formation of a non-uniform opaque film.

Comparative Example 2

Polymer with 2.4-pentanedione

A composition comprising the Resin Mixture from Example A (1.0 gm),aluminum trimethoxyethoxide solution from Example C (1.6 gm),2,4-pentane dione (0.28 gm), and water (0.05 gm) is prepared asdescribed in Examples 1-3. The resulting solution is clear and low inviscosity. The solution, although clear before UV exposure, becomeshighly opaque during UV cure, indicating phase separation of theinorganic component due to the chelating agent not having any reactablefunctional groups.

Comparative Example 3

Polymer Made With Fumed Aluminum Oxide

To the Resin Mixture from Example A (1.76 gm), fumed aluminum oxide(Degussa aluminum oxide-C, 0.24 gm) is added in a glass bottle. Sincethe viscosity is too high to homogenize with a magnetic stirrer,3-methacryloxypropyltrimethoxysilane coupling agent (0.04 gm) is addedto the mixture. The viscosity of the resulting blend gradually lowersand the fumed Al₂ O₃ completely disperses into the resin. The resinviscosity is further lowered by adding 2-methoxyethanol (0.5 gm). Theresulting composition is highly opaque and is not suitable for UV cureapplication. Furthermore, the solution, when aged, tends to precipitatethe filler.

Example 5

Polymer Made With Metal Oxide Sol

A composition containing the Resin from Example B (3.06 gm), the metaloxide precursor from Example C (1.75 gm), MEAA (0.43 gm), and deionizedwater (0.06 gm) is prepared as described in Examples 4-1 to 4-3. Theresulting solution is clear and low in viscosity, and suitable forcoating applications.

Corona Endurance Testing

The compositions from Examples B and 5 are bar-coated onto the polyimidesurface of 3"×3" polyimide (76.2 μm)/adhesive (20.3 μm)/copper (107 μm)laminates (GTS FLEXIBLE MATERIALS INC, Warwick R.I.), and UV-curedgiving clear hard films. The cured films exhibit good adhesion to thesubstrate and no delamination is observed. Corona endurance testing ofthe samples set forth in Table III demonstrates the enhanced performanceof the subject coating over the use of a conventional coating (ExampleB) or no coating with respect to product life, i.e., time to coatingfailure due to corona attack.

                  TABLE III    ______________________________________    RESULTS OF NEEDLE POINT CORONA RESISTANCE TESTING            Sample            Description    Coating (ATME +            Coating Applied                                             Time to    Composition            MEAA)/             Thickness                                       Voltage                                             Failure    Example Resin     Substrate                               (microns)                                       (kV)  (hours)    ______________________________________    no coating        polyimide/                               0       5.2   12.9                      copper    B       0         polyimide/                               18      5.2   41.2                      copper    5       0.4       polyimide/                               9       5.2   99.8                      copper    ______________________________________

Example 6

Polymer Made With Metal Oxide Sol

The metal oxide sol of Example M is admixed with a 1:1 mixture ofbisphenol F epoxy/bisphenol A epoxy (7.7 gm). Volatile components arethen removed under vacuum. Subsequently, Anchor 1222 catalyst (from AirProducts and Chemicals) (0.1 gm) and 8-hydroxyquinoline (0.3 gm) areadded to form a clear resin composition. The resin composition is stableand no gelation is observed even after storage for six months at roomtemperature. The composition is coated on a glass plate and cured in anoven at 180° C. for 3 hrs to give a clear yellow film exhibiting goodadhesion to the substrate.

Example 7

Polymer Made With Metal Oxide Sol

The metal oxide sol of Example N is admixed with bisphenol F epoxy(PY306, Ciba Ceigy, 0.43 gm), phenol novolac epoxy (PY307, Ciba Ceigy,0.57 gm), and cresyl glycidyl ether (Ciba Ceigy, DY023, 0.11 gm), and(3-glycidoxypropyl)trimethoxysilane (0.02 gm). After forming ahomogeneous solution, Anchor 1222 catalyst (0.05 gm) is added togenerate a low viscosity clear epoxy resin composition containing ametal oxide sol. The resin composition is stable and no gelation isobserved even after six months at room temperature. The composition iscoated on a glass plate and heated to 180 ° C. for 3 hrs to give a clearfilm exhibiting good adhesion to the substrate.

Example 8

Polymer Made With Metal Oxide Sol

The metal oxide sol of Example O is admixed with bisphenol F epoxy(PY306, Ciba Ceigy, 4.3 gm), phenol novolac epoxy (PY307, Ciba Ceigy,5.7 gm), and cresyl glycidyl ether (Ciba Ceigy, DY023, 1.1 gm), and(3-glycidoxypropyl)trimethoxysilane (0.06 gm). After forming ahomogeneous solution, Anchor 1222 catalyst (0.5 gm) is added to generatea low viscosity epoxy resin composition containing a metal oxide solbased on zirconium. The resin composition is coated on a glass plate andheated to 180 ° C. for 3 hrs to give a clear film.

Preparation of Epoxy Resin Systems

Seven epoxy resin compositions are prepared as shown in Table IV. Fourresin compositions (Examples 9-12) made with the metal oxide sol ofExamples H-K, respectively. Comparative Example 4 is prepared as acontrol and is not made with a metal oxide additive. ComparativeExamples 5 and 6 contain colloidal silica and fumed aluminum oxide,respectively. All of the compositions are prepared by mixing the epoxy,the diol, the silane, and the metal oxide additives to form homogeneoussolutions and then volatile components are removed under vacuum.Finally, Anchor 1222 catalyst is added to generate low viscosity,solventless resin compositions. The resin compositions of Examples 9-12are stable and no gelation is observed even after three months at roomtemperature. In the case of Comparative Example 6, a high shear mixer isused to disperse the filler before addition of the catalyst.

                  TABLE IV    ______________________________________    EPOXY RESIN FORMULATIONS WT %    EXAMPLE     C4     9      10   11   12   C5   C6    ______________________________________    Aralddite CY179                4.4    4.4    4.4  4.4  4.4  4.4  4.4    epoxy (1)    Bisphenol A diol (2)                2      2      2    2    2    2    2    Sol in Example H   9    Sol in Example I          7.1    Sol in Example J               14.8    Sol in Example K                    4.18    IPA-ST (3)                               1.2    Aluminum oxide C (4)                          0.27    Silane (5)  0.04   0.04   0.04 0.04 0.04 0.04 0.04    Anchor 1222 (6)                0.26   0.26   0.26 0.26 0.26 0.26 0.26    ______________________________________     (1): 3',4Epoxycyclohexylmethyl3,4-epoxycylohexanecarboxylate form Ciba     Geigy     (2): Bisphenol A ethoxylate (2EO/PhOH) from Aldrich Chemical     (3): Colloidal silica (31%) in isopropanol from Nissan Chemical     (4): Fumed aluminum oxide from Degussa     (5): 2(3,4-Epoxycyclohexyl)ethyltrimethoxysilane     (6): Catalyst from Air Products and Chemicals

Corona Endurance Testing

The epoxy resin compositions prepared in Examples 9-12 and ComparativeExamples 4-6 are bar-coated on a polyimide surface of 3"×3" polyimide(76.2 mm)/adhesive (20.3 mm)/copper (107 mm) laminates (GTS FLEXIBLEMATERIALS INC., WARWICK, R.I.) and Copper plates (Cu thickness of 1.045mm), respectively. The coatings are then cured in an oven at 80° C./1 hrand 180 ° C./3 hrs to give pinhole free coatings. All the cured filmsexcept Comparative Example 6 provide clear films. The cured films ofExamples 9-12 exhibit good adhesion to the substrates and nodelamination is observed. Corona testing is performed at roomtemperature using the needle point corona test. The air gap between theneedle point electrode tip and the specimen is 1.0 mm and the appliedvoltage is 5.2 KV AC RAS. Corona endurance testing of the samples setforth in Table V demonstrated that the substantially enhancedperformance of the compositions containing the inventive metal oxidesols over the use of conventional coatings (containing no metal oxideadditive, commercial fumed silica or alumina) with respect to productlife, i.e. time to coating failure due to corona attack. Transmissionelectron micrographs of cured films of the resin compositions containingthe inventive metal oxide sols demonstrate a uniform dispersion ofmaterial that is substantially smaller than those of conventionalfillers (such as fumed alumina and fumed silica). In some cases, TEMsshow no formation of particles, indicating the molecular leveldispersion of the inventive metal oxide sols in the polymer matrix.

                  TABLE V    ______________________________________    RESULTS OF NEEDLE POINT CORONA TESTING                                 COATING  TIME TO    EXAM-  ADDITIVE              THICKNESS                                          FAILURE    PLE    METAL WT % SUBSTRATE  MICRON   HOUR    ______________________________________    C4     none       Pl/Cu      18       42    9      Al, 3.0    Pl/Cu      13       414    10     Al, 2.0    Pl/Cu      13       969    11     Zr, 4.2    Pl/Cu      13       120    12     Ti, 3.1    Pl/Cu      15       250    C5     Si, 2.4    Pl/Cu      23       96    C6     Al, 2.0    Pl/Cu      21       78    C4     none       Cu         120      40    9      Al, 3.0    Cu         120      223    10     Al, 2.0    Cu         120      827    ______________________________________

The polymers of the present invention can be used in virtually anyapplication where conventional polymers are used. For example, thepolymers of the present invention can be used in the plastics industry,semiconductor industry, aerospace industry, automotive industry and thelike. Specific examples of the numerous applications of end uses of thepolymers of the present invention include insulating materials,containers, aerospace composites, dielectric substrates, microelectronicdevices, printed circuit boards, tubes, pipes, consumer goods, housingmaterials, etc.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

What is claimed is:
 1. A polymer prepared from a mixture comprising:a polymerization material; and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor.
 2. The polymer according to claim 1, wherein the polycondensation product comprises about 2 to about 5,000 monomers of the partially hydrolyzed chelated metal oxide precursor.
 3. The polymer according to claim 1, wherein the partially hydrolyzed chelated metal oxide precursor comprises a metal and the metal comprises at least one of an alkaline earth metal, a transition metal or a Group 3A metal.
 4. The polymer according to claim 1, wherein the partially hydrolyzed chelated metal oxide precursor comprises a metal and the metal comprises at least one of aluminum, calcium, magnesium, tin, titanium, zinc or zirconium.
 5. The polymer according to claim 1, wherein the partially hydrolyzed chelated metal oxide precursor comprises a multifunctional compound containing at least one chelating group coordinated to at least one of an alkaline earth metal, a transition metal or a Group 3A metal.
 6. The polymer according to claim 1, wherein the polycondensation product has an average diameter less than about 10 nm.
 7. The polymer according to claim 1, wherein the polymerization material comprises at least one of an acrylic resin, an unsaturated polyester resin, a saturated polyester resin, an alkyl resin, a vinyl ester resin, a polyurethane resin, an epoxy resin, a phenol resin, an urea-aldehyde resin, a polyvinyl aromatic, a maleimide resin, a polyvinyl halide resin, a polyolefin, a polyorganosiloxane, an amino resin, a polyamide, a polyetherimide, a polyphenylene sulfide resin, an aromatic polysulfone, a polyamideimide, a polyesterimide, a polyesteramideimide, a polyvinyl acetal, a fluorinated polymer, or a polycarbonate.
 8. A prepolymer mixture comprising:a polymerization material; and a metal oxide sol comprising a liquid and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor.
 9. The prepolymer mixture according to claim 8, wherein the partially hydrolyzed chelated metal oxide precursor is made from a metal oxide precursor, and the metal oxide precursor comprises at least one of aluminum triethoxide, aluminum isopropoxide, aluminum sec-butoxide, aluminum tri-t-butoxide, aluminum lactate, aluminum chloride, aluminum bromide, titanium methoxide, titanium ethoxide, titanium isopropoxide, titanium propoxide, titanium butoxide, titanium ethylhexoxide, titanium (triethanolaminato)isopropoxide, titanium bis(ammonium lacto)dihydroxide, titanium bis(ethyl acetoacetato)diisopropoxide, titanium bis(2,4-pentanedionate)diisopropoxide, titanium chloride, titanium bromide, zirconium ethoxide, zirconium isopropoxide, zirconium propoxide, zirconium sec-butoxide, zirconium t-butoxide, zirconium acetate, zirconium citrate, zirconium chloride or zirconium bromide.
 10. The prepolymer mixture according to claim 8, wherein the partially hydrolyzed chelated metal oxide precursor is made by contacting a metal oxide precursor with a multifunctional compound, the multifunctional compound comprising at least one of acrylic acid/maleic acid copolymer, alkoxylated diamines, alkyl-diaminepolyacetic acids, aminoalkylphosphonic acid, amino tris(methylene phosphonic acid), anthranilic acid, benzotriazole, citric acid, diethylenetriamine pentaacetic acid, diethylenetriamine penta(methylene phosphonic acid), ethylenediaminetetraacetic acid, gluconic acid, glucoheptonoic acid, hexamethylenediamine tetra(methylene phosphonic acid), lignosulfonic acids, 2-(methacryloyloxy)ethyl acetoacetate, 5-(methacryloyloxy)methyl salicylic acid, 4-methacryloylamino salicylic acid, hydroxyethyl salicylate, hydroxyethyl salicylamide, methylvinyl ether/maleic acid copolymer, o-hydroxybenzoylacetone, 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, 3-hydroxy-2-methyl-4-pyrone, 8-hydroxyquinolone, N-hydroxyethylenediamine triacetic acid, hydroxy-ethylidene diphosphonic acid, hydroxyethane diphosphonic acid, nitrilotriacetic acid, sorbitol, tolyltrizole, o-hydroxybenzoylacetone, 2-hydroxydibenzoylmethane or N-(acetoacetyl)glycine.
 11. The prepolymer mixture according to claim 8, wherein the partially hydrolyzed chelated metal oxide precursor comprises a metal and the metal comprises at least one of an alkaline earth metal, a transition metal or a Group 3A metal.
 12. The prepolymer mixture according to claim 8, wherein the polymerization material comprises at least one of an acrylic resin, an unsaturated polyester resin, a saturated polyester resin, an alkyd resin, a vinyl ester resin, a polyurethane resin, an epoxy resin, a phenol resin, an urea-aldehyde resin, a polyvinyl aromatic, a maleimide resin, a polyvinyl halide resin, a polyolefin, a polyorganosiloxane, an amino resin, a polyamide, a polyetherimide, a polyphenylene sulfide resin, an aromatic polysulfone, a polyamideimide, a polyesterimide, a polyesteramideimide, a polyvinyl acetal, a fluorinated polymer, or a polycarbonate.
 13. The prepolymer mixture according to claim 8, wherein the polymerization material comprises a thermosetting resin.
 14. The prepolymer mixture according to claim 8 comprising:from about 30% to about 99.9% by weight of the polymerization material; and from about 0.1 % to about 70% by weight of the metal oxide sol comprising the liquid and the polycondensation product of the partially hydrolyzed chelated metal oxide precursor.
 15. A process for making a polymer comprising:contacting a polymerization material with a metal oxide sol comprising a liquid and a polycondensation product of a partially hydrolyzed chelated metal oxide precursor to form a mixture; and at least one of polymerizing or curing the mixture.
 16. The process according to claim 15, further comprising the step of removing said liquid from the mixture prior to the step of at least one of polymerizing or curing the mixture.
 17. The process according to claim 15, further comprising the step of removing said liquid from the mixture after the step of at least one of polymerizing or curing the mixture.
 18. The process according to claim 15, wherein the polycondensation product has an average diameter less than about 10 nm.
 19. The process according to claim 15, wherein the polycondensation product comprises about 3 to about 1,000 monomers of the partially hydrolyzed chelated metal oxide precursor.
 20. The process according to claim 15, wherein the metal oxide sol is made by a process comprisingcontacting a metal oxide precursor with a multifunctional compound in a liquid to provide a chelated metal oxide precursor; contacting the chelated metal oxide precursor with a hydrolyzing agent to provide partially hydrolyzed chelated metal oxide precursor monomers; and permitting the partially hydrolyzed chelated metal oxide precursor monomers to polycondense thereby forming the metal oxide sol comprising the liquid and the polycondensation product of the partially hydrolyzed chelated metal oxide precursor.
 21. The process according to claim 15, wherein the polymerization material comprises at least one of an acrylic resin, an unsaturated polyester resin, a saturated polyester resin, an alkyd resin, a vinyl ester resin, a polyurethane resin, an epoxy resin, a phenol resin, an urea-aldehyde resin, a polyvinyl aromatic, a maleimide resin, a polyvinyl halide resin, a polyolefin, a polyorganosiloxane, an amino resin, a polyamide, a polyetherimide, a polyphenylene sulfide resin, an aromatic polysulfone, a polyamideimide, a polyesterimide, a polyesteramideimide, a polyvinyl acetal, a fluorinated polymer, or a polycarbonate.
 22. The process according to claim 15, wherein the partially hydrolyzed chelated metal oxide precursor comprises a multifunctional compound containing at least one chelating group coordinated to at least one of an alkaline earth metal, a transition metal or a Group 3A metal. 